- vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 37744] SVOM/MXT upper limit on GRB 250314A
by GCN Circulars 15 Mar '25

15 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39729 SUBJECT: SVOM/MXT upper limit on GRB 250314A DATE: 25/03/15 07:13:31 GMT FROM: Diego Gotz at CEA <diego.gotz(a)cea.fr> D. Götz (CEA), F. Robinet (IJCLab), H. Goto (CEA), C. Plasse (CEA), P. Maggi (ObAS), M. Moita (CEA), C. van Hove (IJCLab) on behalf of the MXT team report: The field of GRB 250310A (Wange et al. GCN 39719, Li et al. 39728) was observed by MXT promptly after the SVOM slew starting at 12:59:55 UT, i.e. 193 s after ECLAIRs trigger.… [View More]

1 0

[vsnet-grb-info 37743] GRB250314A: SVOM/VT upper limit
by GCN Circulars 15 Mar '25

15 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39728 SUBJECT: GRB250314A: SVOM/VT upper limit DATE: 25/03/15 05:04:43 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> H.L. Li (NAOC), R.-Z. Li (YNAO, CAS), Y. Wang (PMO, CAS), J.X. Cao, D.F. Kong (GXU), L.P. Xin, Y. L. Qiu, C. Wu, Z.H. Yao, Y.N. Ma, X.H. Han, J. Wang, W.J. Xie, Y. Xu, H.B. Cai, J.Y. Wei (NAOC), J. Palmerio (CEA) report on behalf of the SVOM team: SVOM performed an automatic slew on the burst triggered by SVOM/ECLAIRs (Wang et al., GCN … [View More]

1 0

[vsnet-grb-info 37742] GRB 250314A: NOT near-infrared candidate counterpart
by GCN Circulars 15 Mar '25

15 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39727 SUBJECT: GRB 250314A: NOT near-infrared candidate counterpart DATE: 25/03/15 04:30:21 GMT FROM: Daniele B. Malesani at IMAPP / Radboud University <d.malesani(a)astro.ru.nl> D. B. Malesani (DAWN/NBI), G. Corcoran (UCD), L. Izzo (INAF/OAC and DARK/NBI), B. Schneider (LAM), J. Palmerio (CEA/Irfu), A. Henderson de la Fuente (NOT) report on behalf of a larger collaboration: We observed the field of the SVOM GRB 250314A (Wang et al., GCN 39719) … [View More]

1 0

[vsnet-grb-info 37741] GRB 250313A: Fermi GBM Detection
by GCN Circulars 15 Mar '25

15 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39726 SUBJECT: GRB 250313A: Fermi GBM Detection DATE: 25/03/15 02:17:47 GMT FROM: eliza.neights(a)gmail.com Eliza Neights (George Washington University, NASA Goddard Space Flight Center), M. Godwin (UAH), C. Meegan (UAH) and O.J. Roberts (USRA) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 14:34:33.69 UT on 13 March 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250313A (trigger 763569278/250313607), which was … [View More]

1 0

[vsnet-grb-info 37740] GRB 250313A: CALET Gamma-Ray Burst Monitor detection
by GCN Circulars 15 Mar '25

15 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39725 SUBJECT: GRB 250313A: CALET Gamma-Ray Burst Monitor detection DATE: 25/03/15 01:55:09 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo(a)phys.aoyama.ac.jp> K. Yamaoka (Nagoya U), A. Yoshida, T. Sakamoto, S. Sugita, Y. Kawakubo (AGU), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. … [View More]

1 0

[vsnet-grb-info 37739] GRB 250312B: Fermi GBM Observation
by GCN Circulars 15 Mar '25

15 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39724 SUBJECT: GRB 250312B: Fermi GBM Observation DATE: 25/03/15 00:56:42 GMT FROM: Lorenzo Scotton at UAH <lscottongcn(a)outlook.com> L. Scotton (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 20:36:56.64 UT on 12 March 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250312B (trigger 763504621/250312859), which was also localized by Swift/BAT-GUANO (J. DeLaunay et al. 2025, GCN 39708).… [View More]

1 0

[vsnet-grb-info 37738] GRB 250313A: Swift-XRT observations
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39723 SUBJECT: GRB 250313A: Swift-XRT observations DATE: 25/03/14 23:06:25 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> M. A. Williams (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), S. Dichiara (PSU), J.A. Kennea (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed … [View More]follow-up observations of the Fermi/LAT-detected burst GRB 250313A, collecting 6.3 ks of Photon Counting (PC) mode data between T0+30.7 ks and T0+82.7 ks. Seven uncatalogued X-ray sources have been detected, however none of them is above the RASS limit or shows definitive signs of fading. Therefore, at the present time we cannot identify which, if any, is the afterglow. Details of these sources are given below: Source 1: RA (J2000.0): 278.5986 = 18:34:23.66 Dec (J2000.0): +53.8117 = +53:48:42.1 Error: 5.7 arcsec (radius, 90% conf.) Count-rate: (3.20 [+1.07, -0.89])e-3 ct s^-1 Distance: 360 arcsec from Fermi/LAT position. Flux: (1.13 [+0.38, -0.32])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 2: RA (J2000.0): 278.4773 = 18:33:54.54 Dec (J2000.0): +53.6792 = +53:40:45.1 Error: 5.9 arcsec (radius, 90% conf.) Count-rate: (1.23 [+0.71, -0.54])e-3 ct s^-1 Distance: 184 arcsec from Fermi/LAT position. Flux: (5.1 [+2.9, -2.2])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 3: RA (J2000.0): 278.7435 = 18:34:58.45 Dec (J2000.0): +53.8112 = +53:48:40.2 Error: 6.1 arcsec (radius, 90% conf.) Count-rate: (1.19 [+0.90, -0.67])e-3 ct s^-1 Distance: 560 arcsec from Fermi/LAT position. Flux: (2.6 [+2.0, -1.5])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 4: RA (J2000.0): 278.7131 = 18:34:51.13 Dec (J2000.0): +53.8208 = +53:49:14.7 Error: 6.9 arcsec (radius, 90% conf.) Count-rate: (2.16 [+0.95, -0.76])e-3 ct s^-1 Distance: 532 arcsec from Fermi/LAT position. Flux: (2.38 [+1.04, -0.83])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 5: RA (J2000.0): 278.5290 = 18:34:6.96 Dec (J2000.0): +53.8678 = +53:52:04.2 Error: 8.1 arcsec (radius, 90% conf.) Count-rate: (1.57 [+0.84, -0.65])e-3 ct s^-1 Distance: 532 arcsec from Fermi/LAT position. Flux: (6.4 [+3.4, -2.6])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 6: RA (J2000.0): 278.5496 = 18:34:11.90 Dec (J2000.0): +53.7202 = +53:43:12.8 Error: 5.7 arcsec (radius, 90% conf.) Count-rate: (1.35 [+0.73, -0.55])e-3 ct s^-1 Distance: 41 arcsec from Fermi/LAT position. Flux: (8.6 [+4.7, -3.5])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 7: RA (J2000.0): 278.6648 = 18:34:39.55 Dec (J2000.0): +53.6612 = +53:39:40.2 Error: 7.4 arcsec (radius, 90% conf.) Count-rate: (7.5 [+6.0, -4.6])e-4 ct s^-1 Distance: 356 arcsec from Fermi/LAT position. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021822. This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/39723. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37737] GRB250314A: SVOM/VT lack of bright optical candidate from VHF data
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39722 SUBJECT: GRB250314A: SVOM/VT lack of bright optical candidate from VHF data DATE: 25/03/14 16:16:43 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> J. T. Palmerio (CEA), L.P. Xin (NAOC), S. D. Vergani (Obs. Paris), Y. Wang (PMO, CAS), Rui-Zhi Li (YNAO, CAS), Y. L. Qiu, H.L. Li., C. Wu, Z.H. Yao, Y.N. Ma, X.H. Han, H.B. Cai, J.Y. Wei (NAOC), Y. Canton, M. Garnichey, (Obs. Paris) report on behalf of the SVOM/VT team: After the trigger by SVOM/… [View More]

1 0

[vsnet-grb-info 37736] Konus-Wind detection of GRB 250313A
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39721 SUBJECT: Konus-Wind detection of GRB 250313A DATE: 25/03/14 16:07:45 GMT FROM: Dmitry Frederiks at Ioffe Institute <fred(a)mail.ioffe.ru> D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 250313A (Fermi-GBM detection: Fermi GBM team, GCN 39703; BALROG localization: Preis & Greiner, GCN 39704; Fermi-LAT detection: Di Lalla et al., GCN 39711; … [View More]

1 0

[vsnet-grb-info 37735] Konus-Wind detection of GRB 250308A
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39720 SUBJECT: Konus-Wind detection of GRB 250308A DATE: 25/03/14 15:54:17 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, A. Tsvetkova, M. Ulanov, and T. Cline on behalf of the Konus-Wind team, report: The short-duration GRB 250308A (SVOM-GRM detection: Wang et al., GCNs 39632, 39636; IPN triangulation: Kozyrev et al., GCN 39653; CALET-GBM detection: Kawakubo et al., GCN 39663; … [View More]

1 0

[vsnet-grb-info 37734] GRB 250314A: SVOM detection of a burst
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39719 SUBJECT: GRB 250314A: SVOM detection of a burst DATE: 25/03/14 14:12:08 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> Y. Wang (PMO, CAS), Rui-Zhi Li (YNAO, CAS), M. Brunet, H. Yang (IRAP), T.Maiolino (LUPM) on behalf of the SVOM mission team. SVOM/ECLAIRs triggered on the gamma-ray burst GRB 250314A (SVOM burst-id sb25031405) starting at 2025-03-14T12:56:42 UTC (Tb). The following trigger information was received on the ground with low latency … [View More]

1 0

[vsnet-grb-info 37733] EP250311a/GRB 250311A: Correction to EP-WXT detection time
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39718 SUBJECT: EP250311a/GRB 250311A: Correction to EP-WXT detection time DATE: 25/03/14 08:43:16 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> X. Mao (NAO, CAS), Y. J. Zhang (THU), Y. L. Hua (PMO, CAS), Z. X. Ling (NAO, CAS) report on behalf of the Einstein Probe team: The detection time for the transient EP250311a/GRB 250311A reported in GCN 39664 is incorrect: the corrected EP-WXT detection time is 2025-03-11T01:55:13 (UTC). We apologize for … [View More]

1 0

[vsnet-grb-info 37732] GRB 250313B: SVOM/GRM observation of a soft bright short burst
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39717 SUBJECT: GRB 250313B: SVOM/GRM observation of a soft bright short burst DATE: 25/03/14 07:37:23 GMT FROM: wenlongzhang2018(a)163.com SVOM/GRM team: Wen-Long Zhang, Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Nicolas Dagoneau (CEA), Maria-Grazia Bernardini (INAF-OAB), Jean-Luc Atteia (IRAP), Frédéric Piron (LUPM) Report on behalf of the SVOM team: SVOM/GRM was triggered in-flight by GRB 250313B … [View More]

1 0

[vsnet-grb-info 37731] GRB 250313A: SVOM/GRM observation of a bright long burst
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39716 SUBJECT: GRB 250313A: SVOM/GRM observation of a bright long burst DATE: 25/03/14 07:18:32 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> SVOM/GRM team: Chen-Wei Wang, Wen-Jun Tan, Yan-Qiu Zhang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Bertrand Cordier, Nicolas Dagoneau (CEA), Maria-Grazia Bernardini (INAF-OAB), Jean-Luc Atteia (IRAP), Frédéric Piron (LUPM) Report on behalf of the SVOM team: … [View More]

1 0

[vsnet-grb-info 37730] LIGO/Virgo/KAGRA S250206dm & FRB 20250206A: Nondetection of Repeating Bursts from FRB 20250206A with FAST
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39715 SUBJECT: LIGO/Virgo/KAGRA S250206dm & FRB 20250206A: Nondetection of Repeating Bursts from FRB 20250206A with FAST DATE: 25/03/14 03:56:23 GMT FROM: gaosj(a)smail.nju.edu.cn Shi-Jie Gao (NJU), Xiang-Dong Li (NJU), Yi-Xuan Shao (NJU), Ping Zhou (NJU) and Pei Wang (NAOC) report: Following the detection of the binary compact object merger event S250206dm by the LIGO-Virgo-KAGRA Collaboration (GCN [39175](https://gcn.nasa.gov/circulars/39175)), the … [View More]

1 0

[vsnet-grb-info 37729] GRB 250313A: AstroSat CZTI detection of a bright long burst
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39714 SUBJECT: GRB 250313A: AstroSat CZTI detection of a bright long burst DATE: 25/03/14 03:34:39 GMT FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in> A. Dasgupta (BITS Pilani, Hyderabad), G. Waratkar (IITB), M. Tembhurnikar (IUCAA), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat … [View More]

1 0

[vsnet-grb-info 37728] IceCube-250309A: MASTER detection of J140105.33-091631.6 blazar flare with Zhirkov effect
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39713 SUBJECT: IceCube-250309A: MASTER detection of J140105.33-091631.6 blazar flare with Zhirkov effect DATE: 25/03/14 02:36:51 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> K. Labzina, K.Zhirkov, V.Lipunov, E.Gorbovskoy, A.Kuznetsov, G.Antipov, D.Vlasenko, A.Kuznetsov, N.Tyurina, P.Balanutsa, A.Chasovnikov, V.Topolev, Ya.Kechin, V.Senik (Lomonosov MSU), O.Gress, N.Budnev, O.Ershova (ISU), C.Francile, F. … [View More]

1 0

[vsnet-grb-info 37727] Fermi trigger No 763581136: Global MASTER-Net observations report
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39712 SUBJECT: Fermi trigger No 763581136: Global MASTER-Net observations report DATE: 25/03/14 02:16:43 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, … [View More]F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB250313.74 (trigger No 763581136,18h 42m 24.00s , +00d 58m 58.8s, R=6.27) errorbox 27520 sec after notice time and 27564 sec after trigger time at 2025-03-14 01:31:35 UT, with upper limit up to 18.0 mag. The observations began at zenith distance = 56 deg. The sun altitude is -21.3 deg. The galactic latitude b = 2 deg., longitude l = 33 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2811247 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 27594 | 2025-03-14 01:31:35 | MASTER-Kislovodsk | (18h 39m 04.76s , +01d 26m 30.2s) | C | 60 | 17.6 | 27993 | 2025-03-14 01:38:13 | MASTER-Kislovodsk | (18h 38m 47.91s , -00d 27m 18.2s) | C | 60 | 17.6 | 28073 | 2025-03-14 01:39:33 | MASTER-Kislovodsk | (18h 40m 24.11s , +03d 18m 32.2s) | C | 60 | 17.1 | 28152 | 2025-03-14 01:40:53 | MASTER-Kislovodsk | (18h 23m 49.44s , +01d 26m 56.6s) | C | 60 | 17.9 | 28232 | 2025-03-14 01:42:12 | MASTER-Kislovodsk | (18h 25m 16.69s , +03d 20m 34.7s) | C | 60 | 17.3 | 28312 | 2025-03-14 01:43:32 | MASTER-Kislovodsk | (18h 23m 35.70s , -00d 26m 52.0s) | C | 60 | 18.0 | 28391 | 2025-03-14 01:44:52 | MASTER-Kislovodsk | (18h 43m 03.83s , +05d 12m 24.2s) | C | 60 | 17.0 | 28471 | 2025-03-14 01:46:11 | MASTER-Kislovodsk | (18h 39m 53.31s , -02d 21m 38.9s) | C | 60 | 16.6 | 28551 | 2025-03-14 01:47:31 | MASTER-Kislovodsk | (18h 27m 53.45s , +05d 14m 26.6s) | C | 60 | 17.4 | 28630 | 2025-03-14 01:48:51 | MASTER-Kislovodsk | (18h 54m 10.70s , +01d 26m 14.1s) | C | 60 | 17.5 | 28710 | 2025-03-14 01:50:10 | MASTER-Kislovodsk | (18h 53m 58.89s , -00d 29m 39.5s) | C | 60 | 16.4 | 28791 | 2025-03-14 01:51:31 | MASTER-Kislovodsk | (18h 55m 40.16s , +03d 20m 06.9s) | C | 60 | 17.2 | 28870 | 2025-03-14 01:52:51 | MASTER-Kislovodsk | (18h 55m 09.08s , -02d 21m 42.2s) | C | 60 | 16.7 | 28950 | 2025-03-14 01:54:11 | MASTER-Kislovodsk | (18h 24m 37.00s , -02d 20m 34.3s) | C | 60 | 17.6 | 29030 | 2025-03-14 01:55:30 | MASTER-Kislovodsk | (18h 31m 39.50s , +07d 07m 00.6s) | C | 60 | 16.8 | 29110 | 2025-03-14 01:56:50 | MASTER-Kislovodsk | (18h 42m 08.14s , -04d 15m 24.0s) | C | 60 | 16.6 | 29269 | 2025-03-14 01:59:30 | MASTER-Kislovodsk | (18h 46m 57.68s , +07d 08m 43.9s) | C | 60 | 17.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/39712. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37726] GRB 250313A: Fermi-LAT detection
by GCN Circulars 14 Mar '25

14 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39711 SUBJECT: GRB 250313A: Fermi-LAT detection DATE: 25/03/14 00:13:09 GMT FROM: Rahul Gupta at NASA GSFC <rahul.gupta(a)nasa.gov> N. Di Lalla (Stanford Univ.), R. Gupta (NASA GSFC), and M. Arimoto (Kanazawa Univ.) report on behalf of the Fermi-LAT Collaboration: On March 13, 2025, Fermi-LAT detected high-energy emission from GRB 250313A, which was also detected by Fermi-GBM (trigger 763569278 / 250313607, GCN 39703). The best LAT on-ground … [View More]

1 0

[vsnet-grb-info 37725] GRB 250313A: Swift ToO observations
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39710 SUBJECT: GRB 250313A: Swift ToO observations DATE: 25/03/13 23:18:11 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Fermi/LAT GRB 250313A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021822 Any uncatalogued X-ray sources detected in this analysis will be reported on … [View More]

1 0

[vsnet-grb-info 37724] EP250304a: Pan-STARRS r and i-band imaging and photometry
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39709 SUBJECT: EP250304a: Pan-STARRS r and i-band imaging and photometry DATE: 25/03/13 20:31:31 GMT FROM: James Gillanders at University of Oxford <jhgillanders.astro(a)gmail.com> J. H. Gillanders (Oxford), M. Huber, K. C. Chambers (IfA, Univ. Hawaii), S. J. Smartt, K. W. Smith, S. Srivastav (Oxford), M. Nicholl, D. Young, M. Fulton (QUB), T.-W. Chen (NCU, Taiwan) A. S. B. Schultz, T. de Boer, J. Fairlamb, G. Paek, C. C. Lin, T. Lowe, E. Magnier, P. … [View More]

1 0

[vsnet-grb-info 37723] GRB 250312B: Swift/BAT-GUANO localization skymap of a burst
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39708 SUBJECT: GRB 250312B: Swift/BAT-GUANO localization skymap of a burst DATE: 25/03/13 19:55:40 GMT FROM: Jimmy DeLaunay at Penn State <delauj2(a)gmail.com> James DeLaunay (PSU), Samuele Ronchini (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 250312B onboard (T0: 2025-03-12T20:36:56.64 UTC, Fermi trig 763504621) The Fermi notice, distributed in … [View More]near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 12.4 in a 8.192 s analysis time bin, starting at T0 - 2.048 s. Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2025. in prep) The 90% credible area is 10,136 deg2 and the 50% credible area is 2,853 deg2. The integrated probability inside the coded field of view is 1%. The NITRATES skymap is consistent with the Fermi localization reported in the final position notice (GCN 39692). The combined Fermi/GBM+NITRATES 90% credible area is 1,014 deg2 and the 50% credible area is 223 deg2. A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=763504651/#:~:te… The probability skymap and joint skymap files can be downloaded from the links here [skymap_fits_file](https://guano.swift.psu.edu/files/763504651/0_n_PROBMAP) [joint_skymap_fits_file](https://guano.swift.psu.edu/files/763504651/0_n_JOI… Instructions on how to read and manipulate this map can be found here: https://guano.swift.psu.edu/documentation More details about this burst can be found on the trigger report page here: https://guano.swift.psu.edu/trigger_report?id=763504651 GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/ View this GCN Circular online at https://gcn.nasa.gov/circulars/39708. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37722] EP trigger ID 01709061302: Lick/Kast spectroscopy with the 3 m Shane telescope
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39707 SUBJECT: EP trigger ID 01709061302: Lick/Kast spectroscopy with the 3 m Shane telescope DATE: 25/03/13 19:38:57 GMT FROM: Weikang Zheng at UC Berkeley <weikang(a)berkeley.edu> WeiKang Zheng, Thomas G. Brink, Alexei V. Filippenko (UCB), Andy Skemer, Naunet Leonhardes-Barboza, Jordan Forman, Mayra Gutierrez, Isabelle Jones, Ravjit Kaur, Petra Mengistu, Avi Patel, Anavi Uppal, Nicole Wolff, and Michele Woodland (UCSC), report on behalf of the … [View More]

1 0

[vsnet-grb-info 37721] Fermi GRB 250313A: Global MASTER-Net observations report
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39706 SUBJECT: Fermi GRB 250313A: Global MASTER-Net observations report DATE: 25/03/13 19:01:16 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta,… [View More] R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 250313A ( Fermi GBM team, GCN 39703) errorbox 6499 sec after notice time and 6531 sec after trigger time at 2025-03-13 16:23:25 UT, with upper limit up to 19.2 mag. The observations began at zenith distance = 64 deg. The sun altitude is -40.5 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 250313A errorbox 13836 sec after notice time and 13867 sec after trigger time at 2025-03-13 18:25:41 UT, with upper limit up to 16.3 mag. The observations began at zenith distance = 79 deg. The sun altitude is -34.2 deg. The galactic latitude b = 25 deg., longitude l = 80 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2811112 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 6534 | 2025-03-13 16:23:25 | MASTER-Tunka | (18h 26m 19.46s , +51d 36m 23.5s) | C | 5 | 15.9 | 6539 | 2025-03-13 16:23:25 | MASTER-Tunka | (18h 26m 19.46s , +51d 36m 23.4s) | C | 15 | 16.6 | Coadd 6553 | 2025-03-13 16:23:43 | MASTER-Tunka | (18h 26m 25.64s , +51d 35m 22.8s) | C | 5 | 16.1 | 6570 | 2025-03-13 16:24:01 | MASTER-Tunka | (18h 26m 19.56s , +51d 34m 23.6s) | C | 5 | 16.1 | 6588 | 2025-03-13 16:24:18 | MASTER-Tunka | (18h 26m 25.38s , +51d 34m 41.3s) | C | 5 | 16.0 | 6593 | 2025-03-13 16:24:18 | MASTER-Tunka | (18h 26m 25.37s , +51d 34m 41.2s) | C | 15 | 16.7 | Coadd 6607 | 2025-03-13 16:24:37 | MASTER-Tunka | (18h 26m 22.64s , +51d 36m 18.7s) | C | 5 | 16.1 | 6624 | 2025-03-13 16:24:54 | MASTER-Tunka | (18h 26m 22.61s , +51d 34m 53.1s) | C | 5 | 16.0 | 6645 | 2025-03-13 16:25:14 | MASTER-Tunka | (18h 26m 24.91s , +51d 36m 10.2s) | C | 10 | 16.4 | 6655 | 2025-03-13 16:25:14 | MASTER-Tunka | (18h 26m 24.93s , +51d 36m 10.4s) | C | 30 | 16.9 | Coadd 6669 | 2025-03-13 16:25:37 | MASTER-Tunka | (18h 26m 20.02s , +51d 35m 25.5s) | C | 10 | 16.3 | 6693 | 2025-03-13 16:26:02 | MASTER-Tunka | (18h 26m 19.41s , +51d 36m 26.4s) | C | 10 | 16.4 | 6718 | 2025-03-13 16:26:26 | MASTER-Tunka | (18h 26m 25.99s , +51d 35m 26.4s) | C | 10 | 16.4 | 6728 | 2025-03-13 16:26:26 | MASTER-Tunka | (18h 26m 26.01s , +51d 35m 25.7s) | C | 30 | 17.0 | Coadd 6742 | 2025-03-13 16:26:50 | MASTER-Tunka | (18h 26m 21.05s , +51d 34m 26.9s) | C | 10 | 16.5 | 6763 | 2025-03-13 16:27:12 | MASTER-Tunka | (18h 26m 26.84s , +51d 34m 44.6s) | C | 10 | 16.5 | 6786 | 2025-03-13 16:27:34 | MASTER-Tunka | (18h 26m 23.48s , +51d 36m 23.8s) | C | 10 | 16.5 | 6796 | 2025-03-13 16:27:34 | MASTER-Tunka | (18h 26m 23.48s , +51d 36m 23.5s) | C | 30 | 17.1 | Coadd 6809 | 2025-03-13 16:27:57 | MASTER-Tunka | (18h 26m 23.42s , +51d 34m 40.4s) | C | 10 | 16.5 | 6834 | 2025-03-13 16:28:22 | MASTER-Tunka | (18h 26m 26.91s , +51d 36m 01.6s) | C | 10 | 16.5 | 8874 | 2025-03-13 17:02:22 | MASTER-Tunka | (18h 26m 31.04s , +51d 36m 22.5s) | C | 10 | 16.9 | 8884 | 2025-03-13 17:02:22 | MASTER-Tunka | (18h 26m 31.07s , +51d 36m 23.1s) | C | 30 | 17.5 | Coadd 8919 | 2025-03-13 17:02:22 | MASTER-Tunka | (18h 26m 31.07s , +51d 36m 22.8s) | C | 100 | 18.2 | Coadd 9009 | 2025-03-13 17:02:22 | MASTER-Tunka | (18h 26m 31.05s , +51d 36m 22.9s) | C | 280 | 18.9 | Coadd 9139 | 2025-03-13 17:02:22 | MASTER-Tunka | (18h 26m 31.07s , +51d 36m 23.0s) | C | 540 | 19.2 | Coadd 8899 | 2025-03-13 17:02:47 | MASTER-Tunka | (18h 26m 29.42s , +51d 37m 23.3s) | C | 10 | 16.9 | 8922 | 2025-03-13 17:03:10 | MASTER-Tunka | (18h 26m 35.91s , +51d 36m 23.6s) | C | 10 | 16.9 | 8945 | 2025-03-13 17:03:33 | MASTER-Tunka | (18h 26m 30.59s , +51d 35m 24.2s) | C | 10 | 16.8 | 8955 | 2025-03-13 17:03:33 | MASTER-Tunka | (18h 26m 30.61s , +51d 35m 24.4s) | C | 30 | 17.5 | Coadd 8978 | 2025-03-13 17:04:07 | MASTER-Tunka | (18h 26m 36.90s , +51d 35m 42.9s) | C | 10 | 16.8 | 9010 | 2025-03-13 17:04:38 | MASTER-Tunka | (18h 26m 33.86s , +51d 37m 10.4s) | C | 10 | 16.9 | 9032 | 2025-03-13 17:05:00 | MASTER-Tunka | (18h 26m 33.89s , +51d 35m 44.0s) | C | 10 | 16.8 | 9042 | 2025-03-13 17:05:00 | MASTER-Tunka | (18h 26m 33.90s , +51d 35m 44.3s) | C | 30 | 17.6 | Coadd 9055 | 2025-03-13 17:05:23 | MASTER-Tunka | (18h 26m 37.63s , +51d 37m 14.3s) | C | 10 | 16.9 | 9091 | 2025-03-13 17:06:00 | MASTER-Tunka | (18h 26m 30.94s , +51d 36m 27.3s) | C | 10 | 16.9 | 9113 | 2025-03-13 17:06:21 | MASTER-Tunka | (18h 26m 31.10s , +51d 37m 28.0s) | C | 10 | 16.9 | 9123 | 2025-03-13 17:06:21 | MASTER-Tunka | (18h 26m 31.13s , +51d 37m 28.4s) | C | 30 | 17.5 | Coadd 9138 | 2025-03-13 17:06:46 | MASTER-Tunka | (18h 26m 37.27s , +51d 36m 28.0s) | C | 10 | 17.0 | 9161 | 2025-03-13 17:07:09 | MASTER-Tunka | (18h 26m 30.85s , +51d 35m 29.1s) | C | 10 | 16.9 | 9194 | 2025-03-13 17:07:42 | MASTER-Tunka | (18h 26m 36.43s , +51d 35m 41.8s) | C | 10 | 16.9 | 9204 | 2025-03-13 17:07:42 | MASTER-Tunka | (18h 26m 36.44s , +51d 35m 41.9s) | C | 30 | 17.6 | Coadd 9218 | 2025-03-13 17:08:06 | MASTER-Tunka | (18h 26m 34.84s , +51d 37m 14.2s) | C | 10 | 16.8 | 9240 | 2025-03-13 17:08:28 | MASTER-Tunka | (18h 26m 34.84s , +51d 35m 31.0s) | C | 10 | 16.8 | 9263 | 2025-03-13 17:08:51 | MASTER-Tunka | (18h 26m 37.58s , +51d 37m 22.7s) | C | 10 | 16.8 | 9273 | 2025-03-13 17:08:51 | MASTER-Tunka | (18h 26m 37.55s , +51d 37m 22.5s) | C | 30 | 17.5 | Coadd 9287 | 2025-03-13 17:09:15 | MASTER-Tunka | (18h 26m 31.18s , +51d 36m 32.0s) | C | 10 | 16.9 | 9309 | 2025-03-13 17:09:37 | MASTER-Tunka | (18h 26m 33.16s , +51d 37m 32.2s) | C | 10 | 16.8 | 9331 | 2025-03-13 17:09:59 | MASTER-Tunka | (18h 26m 38.97s , +51d 36m 31.6s) | C | 10 | 16.8 | 9341 | 2025-03-13 17:09:59 | MASTER-Tunka | (18h 26m 38.95s , +51d 36m 32.2s) | C | 30 | 17.4 | Coadd 9369 | 2025-03-13 17:10:38 | MASTER-Tunka | (18h 26m 32.93s , +51d 35m 33.1s) | C | 10 | 16.8 | 9393 | 2025-03-13 17:11:02 | MASTER-Tunka | (18h 26m 39.10s , +51d 35m 41.4s) | C | 10 | 16.8 | 9416 | 2025-03-13 17:11:25 | MASTER-Tunka | (18h 26m 35.66s , +51d 37m 29.0s) | C | 10 | 16.9 | 9426 | 2025-03-13 17:11:25 | MASTER-Tunka | (18h 26m 35.67s , +51d 37m 29.1s) | C | 30 | 17.6 | Coadd 9439 | 2025-03-13 17:11:47 | MASTER-Tunka | (18h 26m 35.80s , +51d 35m 40.3s) | C | 10 | 16.8 | 9461 | 2025-03-13 17:12:09 | MASTER-Tunka | (18h 26m 38.43s , +51d 37m 27.2s) | C | 10 | 16.8 | 9485 | 2025-03-13 17:12:34 | MASTER-Tunka | (18h 26m 32.01s , +51d 36m 36.8s) | C | 10 | 16.9 | 9495 | 2025-03-13 17:12:34 | MASTER-Tunka | (18h 26m 31.99s , +51d 36m 36.9s) | C | 30 | 17.6 | Coadd 9509 | 2025-03-13 17:12:57 | MASTER-Tunka | (18h 26m 33.59s , +51d 37m 37.5s) | C | 10 | 16.9 | 9532 | 2025-03-13 17:13:20 | MASTER-Tunka | (18h 26m 38.97s , +51d 36m 37.6s) | C | 10 | 16.9 | 9558 | 2025-03-13 17:13:46 | MASTER-Tunka | (18h 26m 32.63s , +51d 35m 37.9s) | C | 10 | 16.8 | 9568 | 2025-03-13 17:13:46 | MASTER-Tunka | (18h 26m 32.61s , +51d 35m 38.5s) | C | 30 | 17.6 | Coadd 9587 | 2025-03-13 17:14:15 | MASTER-Tunka | (18h 26m 39.27s , +51d 35m 40.7s) | C | 10 | 16.9 | 9613 | 2025-03-13 17:14:41 | MASTER-Tunka | (18h 26m 36.53s , +51d 37m 18.0s) | C | 10 | 16.8 | 9637 | 2025-03-13 17:15:05 | MASTER-Tunka | (18h 26m 36.60s , +51d 36m 00.4s) | C | 10 | 16.7 | 9647 | 2025-03-13 17:15:05 | MASTER-Tunka | (18h 26m 36.62s , +51d 36m 00.8s) | C | 30 | 17.4 | Coadd 9660 | 2025-03-13 17:15:28 | MASTER-Tunka | (18h 26m 40.68s , +51d 37m 37.4s) | C | 10 | 16.6 | 9681 | 2025-03-13 17:15:50 | MASTER-Tunka | (18h 26m 33.64s , +51d 36m 41.2s) | C | 10 | 16.6 | 9705 | 2025-03-13 17:16:14 | MASTER-Tunka | (18h 26m 34.47s , +51d 37m 42.4s) | C | 10 | 16.7 | 9715 | 2025-03-13 17:16:14 | MASTER-Tunka | (18h 26m 34.48s , +51d 37m 42.4s) | C | 30 | 17.4 | Coadd 9730 | 2025-03-13 17:16:38 | MASTER-Tunka | (18h 26m 39.57s , +51d 36m 42.1s) | C | 10 | 16.8 | 9753 | 2025-03-13 17:17:01 | MASTER-Tunka | (18h 26m 33.48s , +51d 35m 43.6s) | C | 10 | 16.8 | 9783 | 2025-03-13 17:17:31 | MASTER-Tunka | (18h 26m 39.45s , +51d 35m 47.0s) | C | 10 | 16.7 | 9793 | 2025-03-13 17:17:31 | MASTER-Tunka | (18h 26m 39.39s , +51d 35m 48.8s) | C | 30 | 17.5 | Coadd 9805 | 2025-03-13 17:17:53 | MASTER-Tunka | (18h 26m 37.41s , +51d 37m 20.4s) | C | 10 | 16.8 | 9828 | 2025-03-13 17:18:16 | MASTER-Tunka | (18h 26m 37.46s , +51d 36m 02.4s) | C | 10 | 16.8 | 9855 | 2025-03-13 17:18:43 | MASTER-Tunka | (18h 26m 41.32s , +51d 37m 31.8s) | C | 10 | 16.8 | 9865 | 2025-03-13 17:18:43 | MASTER-Tunka | (18h 26m 41.29s , +51d 37m 33.2s) | C | 30 | 17.4 | Coadd 9877 | 2025-03-13 17:19:05 | MASTER-Tunka | (18h 26m 34.82s , +51d 36m 45.9s) | C | 10 | 16.8 | 9904 | 2025-03-13 17:19:32 | MASTER-Tunka | (18h 26m 33.93s , +51d 37m 47.4s) | C | 10 | 16.8 | 9928 | 2025-03-13 17:19:57 | MASTER-Tunka | (18h 26m 40.06s , +51d 36m 46.9s) | C | 10 | 16.9 | 9938 | 2025-03-13 17:19:57 | MASTER-Tunka | (18h 26m 40.07s , +51d 36m 47.3s) | C | 30 | 17.6 | Coadd 9952 | 2025-03-13 17:20:20 | MASTER-Tunka | (18h 26m 35.06s , +51d 35m 48.2s) | C | 10 | 16.9 | 9977 | 2025-03-13 17:20:45 | MASTER-Tunka | (18h 26m 41.26s , +51d 36m 10.4s) | C | 10 | 16.8 | 9999 | 2025-03-13 17:21:07 | MASTER-Tunka | (18h 26m 38.25s , +51d 37m 36.4s) | C | 10 | 16.8 | 10009 | 2025-03-13 17:21:07 | MASTER-Tunka | (18h 26m 38.23s , +51d 37m 36.5s) | C | 30 | 17.5 | Coadd 10021 | 2025-03-13 17:21:29 | MASTER-Tunka | (18h 26m 38.20s , +51d 36m 19.4s) | C | 10 | 16.9 | 10045 | 2025-03-13 17:21:53 | MASTER-Tunka | (18h 26m 41.29s , +51d 37m 25.1s) | C | 10 | 16.8 | 10068 | 2025-03-13 17:22:17 | MASTER-Tunka | (18h 26m 36.40s , +51d 36m 53.4s) | C | 10 | 16.9 | 10078 | 2025-03-13 17:22:17 | MASTER-Tunka | (18h 26m 36.34s , +51d 36m 52.3s) | C | 30 | 17.5 | Coadd 10091 | 2025-03-13 17:22:39 | MASTER-Tunka | (18h 26m 35.75s , +51d 37m 52.4s) | C | 10 | 16.7 | 10118 | 2025-03-13 17:23:06 | MASTER-Tunka | (18h 26m 42.28s , +51d 36m 52.8s) | C | 10 | 16.8 | 10140 | 2025-03-13 17:23:29 | MASTER-Tunka | (18h 26m 35.52s , +51d 35m 53.7s) | C | 10 | 16.8 | 10150 | 2025-03-13 17:23:29 | MASTER-Tunka | (18h 26m 35.53s , +51d 35m 53.4s) | C | 30 | 17.4 | Coadd 10166 | 2025-03-13 17:23:54 | MASTER-Tunka | (18h 26m 40.98s , +51d 36m 05.8s) | C | 10 | 16.8 | 10189 | 2025-03-13 17:24:17 | MASTER-Tunka | (18h 26m 38.98s , +51d 37m 47.3s) | C | 10 | 16.8 | 10211 | 2025-03-13 17:24:39 | MASTER-Tunka | (18h 26m 39.03s , +51d 36m 22.3s) | C | 10 | 16.8 | 10221 | 2025-03-13 17:24:39 | MASTER-Tunka | (18h 26m 39.04s , +51d 36m 22.5s) | C | 30 | 17.4 | Coadd 10235 | 2025-03-13 17:25:03 | MASTER-Tunka | (18h 26m 41.70s , +51d 37m 38.1s) | C | 10 | 16.8 | 10257 | 2025-03-13 17:25:26 | MASTER-Tunka | (18h 26m 36.78s , +51d 36m 56.0s) | C | 10 | 16.8 | 10281 | 2025-03-13 17:25:50 | MASTER-Tunka | (18h 26m 36.93s , +51d 37m 57.5s) | C | 10 | 16.8 | 10291 | 2025-03-13 17:25:50 | MASTER-Tunka | (18h 26m 36.94s , +51d 37m 57.5s) | C | 30 | 17.5 | Coadd 10305 | 2025-03-13 17:26:13 | MASTER-Tunka | (18h 26m 43.13s , +51d 36m 57.2s) | C | 10 | 16.8 | 10329 | 2025-03-13 17:26:38 | MASTER-Tunka | (18h 26m 37.01s , +51d 35m 58.4s) | C | 10 | 16.8 | 10352 | 2025-03-13 17:27:01 | MASTER-Tunka | (18h 26m 43.18s , +51d 36m 20.2s) | C | 10 | 16.8 | 10362 | 2025-03-13 17:27:01 | MASTER-Tunka | (18h 26m 43.20s , +51d 36m 19.9s) | C | 30 | 17.3 | Coadd 10374 | 2025-03-13 17:27:23 | MASTER-Tunka | (18h 26m 39.80s , +51d 37m 43.0s) | C | 10 | 16.8 | 10720 | 2025-03-13 17:33:08 | MASTER-Tunka | (18h 26m 36.56s , +51d 37m 55.9s) | C | 10 | 16.6 | 10744 | 2025-03-13 17:33:32 | MASTER-Tunka | (18h 26m 42.69s , +51d 36m 56.6s) | C | 10 | 16.8 | 10754 | 2025-03-13 17:33:32 | MASTER-Tunka | (18h 26m 42.69s , +51d 36m 56.5s) | C | 30 | 17.5 | Coadd 10767 | 2025-03-13 17:33:55 | MASTER-Tunka | (18h 26m 37.68s , +51d 35m 57.3s) | C | 10 | 16.8 | 10789 | 2025-03-13 17:34:18 | MASTER-Tunka | (18h 26m 44.21s , +51d 36m 18.9s) | C | 10 | 16.8 | 10815 | 2025-03-13 17:34:43 | MASTER-Tunka | (18h 26m 40.39s , +51d 37m 30.3s) | C | 10 | 16.9 | 10825 | 2025-03-13 17:34:43 | MASTER-Tunka | (18h 26m 40.44s , +51d 37m 30.2s) | C | 30 | 17.7 | Coadd 10839 | 2025-03-13 17:35:08 | MASTER-Tunka | (18h 26m 40.46s , +51d 36m 13.0s) | C | 10 | 16.8 | 10862 | 2025-03-13 17:35:30 | MASTER-Tunka | (18h 26m 43.41s , +51d 37m 50.3s) | C | 10 | 16.8 | 10885 | 2025-03-13 17:35:53 | MASTER-Tunka | (18h 26m 36.68s , +51d 37m 01.7s) | C | 10 | 16.9 | 10895 | 2025-03-13 17:35:53 | MASTER-Tunka | (18h 26m 36.66s , +51d 37m 02.1s) | C | 30 | 17.6 | Coadd 10907 | 2025-03-13 17:36:15 | MASTER-Tunka | (18h 26m 38.30s , +51d 38m 01.9s) | C | 10 | 16.9 | 10930 | 2025-03-13 17:36:38 | MASTER-Tunka | (18h 26m 43.27s , +51d 37m 02.6s) | C | 10 | 16.8 | 10953 | 2025-03-13 17:37:01 | MASTER-Tunka | (18h 26m 38.01s , +51d 36m 02.4s) | C | 10 | 16.8 | 10963 | 2025-03-13 17:37:01 | MASTER-Tunka | (18h 26m 38.00s , +51d 36m 03.5s) | C | 30 | 17.6 | Coadd 10976 | 2025-03-13 17:37:24 | MASTER-Tunka | (18h 26m 44.18s , +51d 36m 19.5s) | C | 10 | 16.9 | 11004 | 2025-03-13 17:37:52 | MASTER-Tunka | (18h 26m 41.15s , +51d 38m 04.5s) | C | 10 | 16.8 | 11029 | 2025-03-13 17:38:17 | MASTER-Tunka | (18h 26m 41.16s , +51d 36m 26.7s) | C | 10 | 16.8 | 11039 | 2025-03-13 17:38:17 | MASTER-Tunka | (18h 26m 41.14s , +51d 36m 27.1s) | C | 30 | 17.5 | Coadd 11058 | 2025-03-13 17:38:46 | MASTER-Tunka | (18h 26m 43.88s , +51d 37m 41.9s) | C | 10 | 16.7 | 11205 | 2025-03-13 17:41:14 | MASTER-Tunka | (18h 26m 39.08s , +51d 38m 10.5s) | C | 10 | 16.8 | 11228 | 2025-03-13 17:41:37 | MASTER-Tunka | (18h 26m 44.83s , +51d 37m 10.1s) | C | 10 | 16.8 | 11238 | 2025-03-13 17:41:37 | MASTER-Tunka | (18h 26m 44.80s , +51d 37m 10.9s) | C | 30 | 17.3 | Coadd 11252 | 2025-03-13 17:42:01 | MASTER-Tunka | (18h 26m 39.48s , +51d 36m 12.1s) | C | 10 | 16.8 | 11275 | 2025-03-13 17:42:23 | MASTER-Tunka | (18h 26m 45.26s , +51d 36m 28.7s) | C | 10 | 16.5 | 11299 | 2025-03-13 17:42:47 | MASTER-Tunka | (18h 26m 42.16s , +51d 37m 46.4s) | C | 10 | 16.4 | 11334 | 2025-03-13 17:42:47 | MASTER-Tunka | (18h 26m 42.17s , +51d 37m 46.8s) | C | 80 | 17.2 | Coadd 11323 | 2025-03-13 17:43:11 | MASTER-Tunka | (18h 26m 42.26s , +51d 36m 16.2s) | C | 10 | 16.4 | 12037 | 2025-03-13 17:55:05 | MASTER-Tunka | (18h 26m 44.68s , +51d 36m 59.9s) | C | 10 | 16.9 | 12047 | 2025-03-13 17:55:05 | MASTER-Tunka | (18h 26m 44.69s , +51d 36m 59.7s) | C | 30 | 17.5 | Coadd 12059 | 2025-03-13 17:55:28 | MASTER-Tunka | (18h 26m 48.04s , +51d 38m 17.8s) | C | 10 | 16.8 | 12086 | 2025-03-13 17:55:55 | MASTER-Tunka | (18h 26m 41.99s , +51d 37m 39.3s) | C | 10 | 16.8 | 12201 | 2025-03-13 17:57:25 | MASTER-Tunka | (18h 26m 42.92s , +51d 38m 41.9s) | C | 60 | 16.9 | 13085 | 2025-03-13 18:12:08 | MASTER-Tunka | (18h 26m 50.42s , +51d 38m 12.4s) | C | 60 | 17.1 | 13145 | 2025-03-13 18:12:08 | MASTER-Tunka | (18h 26m 50.39s , +51d 38m 13.0s) | C | 180 | 18.0 | Coadd 13866 | 2025-03-13 18:25:09 | MASTER-Tunka | (18h 26m 53.63s , +51d 38m 41.8s) | C | 60 | 17.3 | 13898 | 2025-03-13 18:25:41 | MASTER-Kislovodsk | (18h 10m 41.76s , +52d 27m 30.9s) | C | 60 | 15.9 | 13989 | 2025-03-13 18:27:12 | MASTER-Kislovodsk | (18h 23m 41.90s , +52d 26m 09.7s) | C | 60 | 15.9 | 14150 | 2025-03-13 18:29:53 | MASTER-Kislovodsk | (18h 22m 06.18s , +54d 19m 08.0s) | C | 60 | 15.5 | 14177 | 2025-03-13 18:30:20 | MASTER-Tunka | (18h 26m 51.05s , +51d 38m 00.9s) | C | 60 | 17.2 | 14489 | 2025-03-13 18:35:33 | MASTER-Tunka | (18h 26m 49.28s , +51d 40m 07.6s) | C | 60 | 17.4 | 14623 | 2025-03-13 18:37:46 | MASTER-Kislovodsk | (18h 10m 37.65s , +52d 27m 19.5s) | C | 60 | 15.8 | 14703 | 2025-03-13 18:39:06 | MASTER-Kislovodsk | (18h 23m 44.86s , +52d 27m 56.3s) | C | 60 | 15.7 | 14811 | 2025-03-13 18:40:54 | MASTER-Tunka | (18h 26m 56.06s , +51d 38m 22.4s) | C | 60 | 17.6 | 14863 | 2025-03-13 18:41:46 | MASTER-Kislovodsk | (18h 22m 08.17s , +54d 19m 55.4s) | C | 60 | 15.9 | 15022 | 2025-03-13 18:44:26 | MASTER-Kislovodsk | (18h 13m 52.92s , +50d 32m 34.5s) | C | 60 | 15.7 | 15102 | 2025-03-13 18:45:45 | MASTER-Kislovodsk | (18h 26m 30.58s , +50d 33m 17.4s) | C | 60 | 15.8 | 15262 | 2025-03-13 18:48:25 | MASTER-Kislovodsk | (18h 10m 39.41s , +52d 28m 11.9s) | C | 60 | 16.3 | 15342 | 2025-03-13 18:49:45 | MASTER-Kislovodsk | (18h 23m 53.56s , +52d 26m 49.5s) | C | 60 | 15.8 | 15501 | 2025-03-13 18:52:24 | MASTER-Kislovodsk | (18h 22m 15.90s , +54d 20m 16.1s) | C | 60 | 16.2 | 15660 | 2025-03-13 18:55:04 | MASTER-Kislovodsk | (18h 13m 54.34s , +50d 32m 38.8s) | C | 60 | 15.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/39706. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37720] GRB 250309B: PRIME near-infrared upper limits in 2nd epoch
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39705 SUBJECT: GRB 250309B: PRIME near-infrared upper limits in 2nd epoch DATE: 25/03/13 18:41:30 GMT FROM: O. Guiffreda at UMD <oriogui(a)umd.edu> O. Guiffreda (UMD), J. Durbak (UMD), E. Troja (U Rome), A. S. Kutyrev (NASA/GSFC), S. B. Cenko (NASA/GSFC) Following up the initial PRIME detection (GCN 39670), the transient field was observed a second time ~3.5 days after the initial Fermi GBM trigger (GCN 39635). At the position of the optical … [View More]

1 0

[vsnet-grb-info 37719] GRB 250313A???: BALROG localization (Fermi Trigger / GRB 250313607)
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39704 SUBJECT: GRB 250313A???: BALROG localization (Fermi Trigger / GRB 250313607) DATE: 25/03/13 16:04:30 GMT FROM: Jochen Greiner at MPE <jcgrog(a)mpe.mpg.de> T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger at 14:34:33 on 13 March 2025 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; … [View More]

1 0

[vsnet-grb-info 37718] GRB 250313A: Fermi GBM Final Real-time Localization
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39703 SUBJECT: GRB 250313A: Fermi GBM Final Real-time Localization DATE: 25/03/13 14:44:53 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply(a)GIOC.nsstc.nasa.gov> The Fermi GBM team reports the detection of a likely LONG GRB At 14:34:33 UT on 13 Mar 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250313A (trigger 763569278.689058 / 250313607). The on-ground calculated location, using the Fermi GBM trigger data, is RA =… [View More]

1 0

[vsnet-grb-info 37717] The EP-WXT trigger 01709132551 is not a real source
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39702 SUBJECT: The EP-WXT trigger 01709132551 is not a real source DATE: 25/03/13 13:25:41 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> J. W. Hu (NAO, CAS), Y. Wang (PMO, CAS), P. Y. Han (HUST), W. D. Zhang (NAO, CAS) on behalf of the Einstein Probe (EP) team: The EP-WXT trigger 01709132551 at the time of 2025-03-13T12:04:16, is not a real source. View this GCN Circular online at https://gcn.nasa.gov/circulars/39702. --- To unsubscribe, open … [View More]

1 0

[vsnet-grb-info 37716] EP250304a: SVOM/VT optical observation
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39701 SUBJECT: EP250304a: SVOM/VT optical observation DATE: 25/03/13 08:06:28 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> R. C. Chen (NJU), L. Lan (NAOC), C. W. Wang, W. J. Tan (IHEP), L. P. Xin, Y. L. Qiu, H. L. Li, Z. H. Yao, Y. Xu, P. P. Zhang, W. J. Xie, J. Wang, X. H. Han, Y. J. Xiao, H. B. Cai, J. Y. Wei (NAOC), J. T. Palmerio (CEA/Irfu) report on behalf of the SVOM mission team. SVOM/VT conducted ToO follow-up observations of the X-ray … [View More]

1 0

[vsnet-grb-info 37715] EP250311a/GRB 250311A: EP-FXT follow-up observation
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39700 SUBJECT: EP250311a/GRB 250311A: EP-FXT follow-up observation DATE: 25/03/13 07:52:04 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> X. Mao (NAO, CAS), Y. J. Zhang (THU), Y. L. Hua (PMO, CAS), Z. X. Ling (NAO, CAS) report on behalf of the Einstein Probe team: Following the detection of the fast X-ray transient EP250311a (Mao et al., GCN 39664), also detected as GRB 250311A by MAXI (Tatano et al., GCN 39660), we performed an observation with … [View More]

1 0

[vsnet-grb-info 37714] ATCA detection of the radio counterpart of GRB 250309B-AT2025dws
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39699 SUBJECT: ATCA detection of the radio counterpart of GRB 250309B-AT2025dws DATE: 25/03/13 07:30:45 GMT FROM: Tao An at SHAO, CAS <antao(a)shao.ac.cn> Tao An, Yuanqi Liu (SHAO, China), Jinjun Geng, Xuefeng Wu (PMO, China), Ailing Wang (IHEP, China) report on behalf of a large collaboration. We report the detection of a radio counterpart to GRB 250309B-AT2025dws (GCN 39629, 39637, 39639) with the Australia Telescope Compact Array (ATCA). We … [View More]

1 0

[vsnet-grb-info 37713] EP250302a: Chandra X-ray Detection
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39698 SUBJECT: EP250302a: Chandra X-ray Detection DATE: 25/03/13 02:48:18 GMT FROM: Brendan O'Connor at Carnegie Mellon University <boconno2(a)andrew.cmu.edu> B. O'Connor (CMU), D. Pasham (MIT), J. Hare (Catholic/GSFC), report on behalf of a larger collaboration: We observed EP250302a (Dai et al., GCN 39556) with the Chandra X-ray Observatory through Director's Discretionary Time (PI: O'Connor) for ~20 ks starting on 2025-03-11 at 14:04:47 UT, … [View More]

1 0

[vsnet-grb-info 37712] GRB 250312A: Swift-XRT refined Analysis
by GCN Circulars 13 Mar '25

13 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39697 SUBJECT: GRB 250312A: Swift-XRT refined Analysis DATE: 25/03/13 01:21:03 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> D.N. Burrows (PSU), M. A. Williams (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB), S. Dichiara (PSU) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 8.3 ks of XRT data for GRB 250312A, from 385 s to 34.7 … [View More]

1 0

[vsnet-grb-info 37711] Fermi Gamma-ray Burst Monitor trigger 763509110/250312911 is not a GRB
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39696 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 763509110/250312911 is not a GRB DATE: 25/03/12 22:57:50 GMT FROM: Lorenzo Scotton at UAH <lscottongcn(a)outlook.com> L. Scotton (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 763509110/250312911 at 21:51:45.47 UT on 12 March 2025, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to SAA … [View More]

1 0

[vsnet-grb-info 37710] Fermi trigger No 763509110: Global MASTER-Net observations report
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39695 SUBJECT: Fermi trigger No 763509110: Global MASTER-Net observations report DATE: 25/03/12 22:16:12 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, … [View More]F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB250312.91 (trigger No 763509110,11h 20m 38.40s , +63d 14m 24.0s, R=3.19) errorbox 38 sec after notice time and 61 sec after trigger time at 2025-03-12 21:52:47 UT, with upper limit up to 17.3 mag. The observations began at zenith distance = 21 deg. The sun altitude is -49.4 deg. The galactic latitude b = 51 deg., longitude l = 139 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2810236 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 67 | 2025-03-12 21:52:47 | MASTER-Kislovodsk | (11h 35m 54.68s , +63d 26m 27.5s) | C | 10 | 16.0 | 82 | 2025-03-12 21:52:47 | MASTER-Kislovodsk | (11h 35m 54.60s , +63d 26m 28.4s) | C | 40 | 17.1 | Coadd 96 | 2025-03-12 21:53:16 | MASTER-Kislovodsk | (11h 35m 54.54s , +63d 26m 29.5s) | C | 10 | 16.0 | 132 | 2025-03-12 21:53:47 | MASTER-Kislovodsk | (11h 35m 54.37s , +63d 26m 30.6s) | C | 20 | 16.8 | 177 | 2025-03-12 21:54:27 | MASTER-Kislovodsk | (11h 20m 23.59s , +63d 23m 11.2s) | C | 30 | 17.1 | 232 | 2025-03-12 21:55:17 | MASTER-Kislovodsk | (11h 20m 23.31s , +63d 23m 12.5s) | C | 40 | 17.3 | 297 | 2025-03-12 21:56:17 | MASTER-Kislovodsk | (11h 20m 22.85s , +63d 23m 13.8s) | C | 50 | 17.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/39695. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37709] Fermi GRB 250312B: Global MASTER-Net observations report
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39694 SUBJECT: Fermi GRB 250312B: Global MASTER-Net observations report DATE: 25/03/12 22:15:40 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta,… [View More] R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 250312B ( Fermi GBM team, GCN 39692) errorbox 1617 sec after notice time and 1650 sec after trigger time at 2025-03-12 21:04:27 UT, with upper limit up to 18.4 mag. The observations began at zenith distance = 25 deg. The sun altitude is -47.1 deg. The galactic latitude b = 11 deg., longitude l = 296 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2810182 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 1681 | 2025-03-12 21:04:27 | MASTER-SAAO | (11h 29m 04.39s , -48d 18m 30.7s) | C | 60 | 18.2 | 3030 | 2025-03-12 21:26:57 | MASTER-SAAO | (11h 29m 01.89s , -48d 17m 08.7s) | C | 60 | 18.2 | 3110 | 2025-03-12 21:28:16 | MASTER-SAAO | (12h 02m 31.64s , -51d 04m 13.5s) | C | 60 | 18.0 | 3170 | 2025-03-12 21:28:16 | MASTER-SAAO | (12h 02m 31.64s , -51d 04m 13.5s) | C | 180 | 18.4 | Coadd 3189 | 2025-03-12 21:29:35 | MASTER-SAAO | (12h 02m 31.65s , -51d 04m 13.4s) | C | 60 | 17.9 | 3268 | 2025-03-12 21:30:54 | MASTER-SAAO | (12h 02m 31.60s , -51d 04m 13.0s) | C | 60 | 17.9 | 3347 | 2025-03-12 21:32:13 | MASTER-SAAO | (12h 02m 31.51s , -51d 04m 12.3s) | C | 60 | 17.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/39694. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37708] GRB 250312A: Enhanced Swift-XRT position
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39693 SUBJECT: GRB 250312A: Enhanced Swift-XRT position DATE: 25/03/12 22:04:03 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 1241 s of XRT Photon Counting mode data and 2 UVOT images for GRB 250312A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the … [View More]

1 0

[vsnet-grb-info 37707] GRB 250312B: Fermi GBM Final Localization
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39692 SUBJECT: GRB 250312B: Fermi GBM Final Localization DATE: 25/03/12 21:55:01 GMT FROM: Lorenzo Scotton at UAH <lscottongcn(a)outlook.com> The Fermi GBM team reports the detection of a likely LONG GRB "At 20:36:56.64 UT on 12 March 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250312B (trigger 763504621/250312859). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 180.86, Dec = -50.96 (J2000 … [View More]

1 0

[vsnet-grb-info 37706] LIGO/Virgo/KAGRA S250304cb: Upper limits from Swift/BAT-GUANO
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39691 SUBJECT: LIGO/Virgo/KAGRA S250304cb: Upper limits from Swift/BAT-GUANO DATE: 25/03/12 20:51:58 GMT FROM: Maia Williams at PSU <mjw6837(a)psu.edu> Maia Williams (PSU), Samuele Ronchini (PSU), Gayathri Raman (PSU), James DeLaunay (PSU), Tyler Parsotan (NASA GSFC), Jamie A. Kennea (PSU), Aaron Tohuvavohu (Caltech) report: Swift/BAT was observing 97.58% of the GW localization probability ([bayestar.multiorder.fits](https://gracedb.ligo.org/api/… [View More]superevents/S250304c…) at merger time. A fraction 43.22% of the GW localization posterior is contained inside the BAT coded FoV. The LVK notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; [Tohuvavohu et al. 2020, ApJ, 900, 1](https://iopscience.iop.org/article/10.3847/1538-4357/aba94f)). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. Using the NITRATES analysis ([DeLaunay + Tohuvavohu 2022, ApJ, 941, 169](https://iopscience.iop.org/article/10.3847/1538-4357/ac9d38)), we searched for emission on 8 timescales from 0.128s to 16.384s in the interval [-20,+20] seconds around the merger time. We find no evidence for a signal, and derive the following upper limits. We quote the 5-sigma flux upper limits in the 15-350 keV band, weighted over the GW localization, for four spectral templates (soft, normal, and hard GRB-like templates described in [arXiv:1612.02395], and spectral shape from GRB170817A [arXiv:1710.05446]) and for four time bins. In units of 10^-7 erg/s/cm^2: |time_bin (s) |soft |normal|hard |GRB170817 |-|-|-|-|-| |0.256 |7.85 |5.54 |5.01 |6.09 |1.024 |3.99 |2.82 |2.55 |3.09 |4.096 |2.12 |1.50 |1.36 |1.65 |16.384 |1.29 |0.91 |0.82 |1.00 The upper limits as function of sky position are plotted here, alongside the GW localization: [https://zenodo.org/records/15008852] The solid and dashed lines indicate the 90% and 50% GW contour levels, respectively. The corresponding fits file is also included. GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: [https://www.swift.psu.edu/guano/] View this GCN Circular online at https://gcn.nasa.gov/circulars/39691. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37705] GRB 250226B: Fermi GBM Observation
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39690 SUBJECT: GRB 250226B: Fermi GBM Observation DATE: 25/03/12 20:16:32 GMT FROM: Jacob Smith at Fermi-GBM Team <jrs0118(a)uah.edu> Jacob Smith (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: At 22:30:23.12 UT on 26 February 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250226B (trigger 762301828/250226938). which was also detected by INTEGRAL SPI-ACS (J. Rodi, et al. 2025, GCN 39519) … [View More]

1 0

[vsnet-grb-info 37704] Swift GRB 250312A: Global MASTER-Net observations report
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39689 SUBJECT: Swift GRB 250312A: Global MASTER-Net observations report DATE: 25/03/12 18:04:11 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta,… [View More]

1 0

[vsnet-grb-info 37703] GRB 250302A: Fermi GBM Observation
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39688 SUBJECT: GRB 250302A: Fermi GBM Observation DATE: 25/03/12 17:18:02 GMT FROM: Marianna Dafčíková at Masaryk University <500025(a)mail.muni.cz> M. Dafcikova (MUNI) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 13:46:32.99 UT on 02 March 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250302A (trigger 762615997/250302574). which was also detected by Swift/BAT-GUANO (DeLaunay et al. … [View More]

1 0

[vsnet-grb-info 37702] GRB 250309B/AT 2025dws: Daochen/RC-10 optical counterpart observation
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39687 SUBJECT: GRB 250309B/AT 2025dws: Daochen/RC-10 optical counterpart observation DATE: 25/03/12 17:01:44 GMT FROM: sqjiang at NAOC <sqjiang(a)bao.ac.cn> S.Q. Jiang (NAOC), S.H. Wang (THU), J. An, X. Liu, Z.P. Zhu, D. Xu (NAOC), S.Y. Fu (HUST), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report: We observed the optical counterpart AT 2025dws (Stein et al., GCN 39639, 39644; Pérez-Fournon et al., GCN 39643; Moskvitin et al., GCN 39645, … [View More]

1 0

[vsnet-grb-info 37701] GRB 250312A: Swift detection of a burst
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39686 SUBJECT: GRB 250312A: Swift detection of a burst DATE: 25/03/12 13:41:19 GMT FROM: K.L. Page at U Leicester <klp5(a)leicester.ac.uk> A. Melandri (INAF-OAR), V. D'Elia (SSDC & INAF-OAR), J. J. DeLaunay (PSU), S. Dichiara (PSU), R. Gupta (NASA GSFC), J. A. Kennea (PSU), M. J. Moss (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB) and M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: … [View More] At 13:24:17 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 250312A (trigger=1294765). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 29.510, -42.404 which is RA(J2000) = 01h 58m 02s Dec(J2000) = -42d 24' 15" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Only the first 8 seconds of the BAT light curve are immediately available. This limited data shows a complex peak structure that extends beyond the T+8s cut-off. The peak count rate was ~1800 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 13:26:33.0 UT, 135.4 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 29.51911, -42.39599 which is equivalent to: RA(J2000) = 01h 58m 04.59s Dec(J2000) = -42d 23' 45.6" with an uncertainty of 1.9 arcseconds (radius, 90% containment). This location is 37 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.79 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 3 (+2.65/-2.31) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 7.29e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 427 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.017. Burst Advocate for this burst is A. Melandri (andrea.melandri AT inaf.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/) View this GCN Circular online at https://gcn.nasa.gov/circulars/39686. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37700] GRB 241213A: VIRT Optical Upper Limit
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39685 SUBJECT: GRB 241213A: VIRT Optical Upper Limit DATE: 25/03/12 13:11:33 GMT FROM: Priya Gokuldass at ERAU <gokuldap(a)my.erau.edu> K. Smith (UVI), P. Gokuldass (ERAU), N. Orange (OrangeWave Innovative Science, LLC), B. Gendre (UVI), D. Morris (NASA), T. Lombardi (Eckerd College), F. George (ERAU), D. Smith (UVI), R. Querrard (UVI), and C. Watson (UVI) report: We observed the field of GRB241213A (Gupta et al., GCN 38547) with the 0.5m Virgin … [View More]

1 0

[vsnet-grb-info 37699] GRB 241228A: VIRT Optical Upper Limit
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39684 SUBJECT: GRB 241228A: VIRT Optical Upper Limit DATE: 25/03/12 13:10:18 GMT FROM: Priya Gokuldass at ERAU <gokuldap(a)my.erau.edu> R. Querrard (UVI), P. Gokuldass (ERAU), N. Orange (OrangeWave Innovative Science, LLC), B. Gendre (UVI), D. Morris (NASA), T. Lombardi (Eckerd College), F. George (ERAU), D. Smith (UVI), K. Smith (UVI), C. Watson (UVI) report: We observed the field of GRB241228A (D'Elia et al., GCN 38681) with the 0.5m Virgin Island … [View More]

1 0

[vsnet-grb-info 37698] GRB 250311A/EP250311a: Optical upper limits with Kinder observations
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39683 SUBJECT: GRB 250311A/EP250311a: Optical upper limits with Kinder observations DATE: 25/03/12 13:01:59 GMT FROM: Janet Chen at National Central University <janetstars(a)gmail.com> A. Sankar. K, M.-H. Lee, A. Aryan, Y.-H. Lee, C.-H. Lai, T.-W. Chen, H.-Y. Hsiao, W.-J. Hou (all NCU), A. K. H. Kong (NTHU), J. Gillanders (Oxford), S. J. Smartt (Oxford/QUB), Y. J. Yang, C.-S. Lin, Y.-C. Pan, C.-C. Ngeow, H.-C. Lin, J.-K. Guo (all NCU), S. Yang, L. L. … [View More]Fan, Z. N. Wang, G. H. Sun (all HNAS), H.-W. Lin (UMich), H. F. Stevance, S. Srivastav, L. Rhodes (all Oxford), M. Nicholl, M. Fulton, T. Moore, K. W. Smith, C. Angus, A. Aamer (all QUB), A. Schultz and M. Huber (both IfA, Hawaii) report: We observed the field of the fast X-ray transient GRB 250311A/EP250311a (Tatano et al., GCN 39660; Mao et al., GCN 39664) using the 40cm SLT and 1 meter LOT telescopes at Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen & Yang et al. 2024, arXiv:2406.09270). The first SLT epoch of observations in the r band started at 15:28 UT on the 11th of March 2025 (MJD = 60745.6442), ~13.52 hrs after the EP trigger, while the first LOT epoch of observations in the r band started at 17:01 UT on the 11th of March 2025 (MJD = 60745.7090), ~ 15.08 hrs after the EP trigger. We utilised the astroalign (Beroiz et al., 2020, A&C, 32, 100384) and astropy (Astropy Collaboration et al., 2022, ApJ, 935, 167) packages to align and stack the individual frames. We did not detect any uncataloged optical counterpart candidate within the EP-WXT localization error circle of radius 2.8 arcminutes in the stacked image. Moreover, we employed the Python-based package AutoPhOT (Brennan & Fraser, 2022, A&A, 667, A62) to perform template subtraction utilizing the "sfft" (Hu, 2022, ApJ, 936, 157) algorithm using a template from SkyMapper DR4 (Onken et., 2024, PASA, 41, e061). We found no evidence of any prominent candidate optical counterpart in the difference image as well. We further employed the Python-based package AutoPhOT to perform PSF photometry on our stacked frames. The details of the observations and measured 3-sigma upper limits (in the AB system) were as follows: Telescope | Filter | MJD (start) | t-t0 (hr) | Exposure (s) | Magnitude | avg. Seeing | med. Airmass SLT | r | 60745.6442 | 13.52 | 300 * 9 | >19.6 | 1".5 | 2.04 LOT | r | 60745.7090 | 15.08 | 300 * 6 | >21.2 | 1".3 | 1.36 The non-detection of any prominent optical counterpart is consistent with Li et al. (GCN 39667). The presented upper limits were calibrated using the field stars from the Pan-STARRS1 catalog and were not corrected for the expected Galactic foreground extinction corresponding to a reddening of A_r = 0.27 mag, respectively, in the direction of the transient (Schlafly & Finkbeiner 2011). View this GCN Circular online at https://gcn.nasa.gov/circulars/39683. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37697] GRB 250223B: Fermi GBM Observation
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39682 SUBJECT: GRB 250223B: Fermi GBM Observation DATE: 25/03/12 10:06:11 GMT FROM: Rushikesh Sonawane at IISER, TVM <rushikesh23(a)iisertvm.ac.in> R. Sonawane (IISER, TVM), R. Hamburg (USRA) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 10:19:23.76 UT on 23 February 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250223B (trigger 761998768/250223430). which was also detected by Swift/BAT-… [View More]

1 0

[vsnet-grb-info 37696] GRB 250311A: Swift-XRT observations
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39681 SUBJECT: GRB 250311A: Swift-XRT observations DATE: 25/03/12 09:58:00 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> J.A. Kennea (PSU), D.N. Burrows (PSU), M. A. Williams (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), R. Brivio (INAF-OAB), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAR) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the … [View More]

1 0

[vsnet-grb-info 37695] GRB 250228A: Fermi GBM Observation
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39680 SUBJECT: GRB 250228A: Fermi GBM Observation DATE: 25/03/12 07:13:25 GMT FROM: Utkarsh Pathak at IIT Bombay <utkarshpathak.07(a)gmail.com> U. Pathak (IIT Bombay), M. Dafčíková (Masaryk U.), and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 07:23:46.16 UT on 28 February 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250228A (trigger 762420231/250228308). which was also detected by Swift/… [View More]

1 0

[vsnet-grb-info 37694] GRB 230509B: 1.3m DFOT Optical observations
by GCN Circulars 12 Mar '25

12 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39679 SUBJECT: GRB 230509B: 1.3m DFOT Optical observations DATE: 25/03/12 06:18:47 GMT FROM: Amit Kumar Ror at ARIES <mitturor77894(a)gmail.com> Amit K. Ror, Anshika Gupta, Pranshu, Shashi B. Pandey, Kuntal Mishra (ARIES) report: We observed the field of GRB 230509B detected by the Swift and Fermi (Evans et al. 2025, GCN 39633; Fermi GBM team, GCN 39635, 39642) with the 1.3m Devasthal Fast Optical Telescope (DFOT), located at the Devasthal … [View More]

1 0

[vsnet-grb-info 37693] IceCube-250309A: Upper limits from a search for additional neutrino events in IceCube
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39678 SUBJECT: IceCube-250309A: Upper limits from a search for additional neutrino events in IceCube DATE: 25/03/11 21:36:06 GMT FROM: Jessie Thwaites at IceCube/U Wisc-Madison <thwaites(a)wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-250309A (https://gcn.nasa.gov/circulars/39631) in a time range of 1000 … [View More]

1 0

[vsnet-grb-info 37692] EP250311a: Global MASTER-Net observations report
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39677 SUBJECT: EP250311a: Global MASTER-Net observations report DATE: 25/03/11 21:18:50 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.… [View More]

1 0

[vsnet-grb-info 37691] GRB 250308A: Swift/BAT-GUANO localization skymap of a short burst
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39676 SUBJECT: GRB 250308A: Swift/BAT-GUANO localization skymap of a short burst DATE: 25/03/11 20:10:54 GMT FROM: Samuele Ronchini at PSU <sjs8171(a)psu.edu> James DeLaunay (PSU), Samuele Ronchini (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 250308A onboard (T0: 2025-03-08T18:06:30.72 UTC, CALET/GBM trig 1425492335 GCN 39663, SVOM/GRM GCN 39632) … [View More]The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 90 seconds of BAT event-mode data from [-45,+45] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 32.5 in a 0.256 s analysis time bin, starting at T0 - 0.064 s. Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2025. in prep) The 90% credible area is 2,693 deg2 and the 50% credible area is 785 deg2. The integrated probability inside the coded field of view is <1%. The NITRATES skymap is consistent with the SVOM/GRM (GCN 39636) and IPN (GCN 39653) localizations. A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=763150025/#:~:te… The probability skymap file can be downloaded from the link here [skymap_fits_file](https://guano.swift.psu.edu/files/763150025/0_n_PROBMAP) Instructions on how to read and manipulate this map can be found here: https://guano.swift.psu.edu/documentation More details about this burst can be found on the trigger report page here: https://guano.swift.psu.edu/trigger_report?id=763150025 GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/ View this GCN Circular online at https://gcn.nasa.gov/circulars/39676. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37690] GRB 250228A: Swift/BAT-GUANO localization skymap of a likely short burst
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39674 SUBJECT: GRB 250228A: Swift/BAT-GUANO localization skymap of a likely short burst DATE: 25/03/11 20:10:49 GMT FROM: Samuele Ronchini at PSU <sjs8171(a)psu.edu> Samuele Ronchini (PSU), James DeLaunay (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 250228A onboard (T0: 2025-02-28T07:23:46.16 UTC, Fermi GCN 39547) The Fermi notice, distributed in … [View More]near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 8.03 in a 0.128 s analysis time bin, starting at T0 - 0.096 s. Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2025. in prep) The 90% credible area is 14,714 deg2 and the 50% credible area is 5,217 deg2. The integrated probability inside the coded field of view is <1%. The joint NITRATES+GBM localization has a 90% credible area of 1171 deg2 and a 50% credible area of 304 deg2 A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=762420261/#:~:te… The probability skymap and joint skymap files can be downloaded from the links here [skymap_fits_file](https://guano.swift.psu.edu/files/762420261/0_n_PROBMAP) [joint_skymap_fits_file](https://guano.swift.psu.edu/files/762420261/0_n_JOI… Instructions on how to read and manipulate this map can be found here: https://guano.swift.psu.edu/documentation More details about this burst can be found on the trigger report page here: https://guano.swift.psu.edu/trigger_report?id=762420261 GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/ View this GCN Circular online at https://gcn.nasa.gov/circulars/39674. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37689] GRB 250226B: Swift/BAT-GUANO localization skymap of a likely long GRB
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39673 SUBJECT: GRB 250226B: Swift/BAT-GUANO localization skymap of a likely long GRB DATE: 25/03/11 20:10:47 GMT FROM: Samuele Ronchini at PSU <sjs8171(a)psu.edu> Samuele Ronchini (PSU), James DeLaunay (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 250226B onboard (T0: 2025-02-26T22:30:23.12 UTC, Fermi GCN 39503, INTEGRAL GCN 39519) The Fermi notice, … [View More]distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 15.1 in a 1.024 s analysis time bin, starting at T0 + 1.79 s. Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2025. in prep) The 90% credible area is 3,416 deg2 and the 50% credible area is 994 deg2. The integrated probability inside the coded field of view is 6%. The joint NITRATES+GBM localization has a 90% credible area of 165 deg2 and a 50% credible area of 36 deg2 A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=762301858/#:~:te… The probability skymap and joint skymap files can be downloaded from the links here [skymap_fits_file](https://guano.swift.psu.edu/files/762301858/0_n_PROBMAP) [joint_skymap_fits_file](https://guano.swift.psu.edu/files/762301858/0_n_JOI… Instructions on how to read and manipulate this map can be found here: https://guano.swift.psu.edu/documentation More details about this burst can be found on the trigger report page here: https://guano.swift.psu.edu/trigger_report?id=762301858 GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/ View this GCN Circular online at https://gcn.nasa.gov/circulars/39673. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37688] GRB 250226A: Swift/BAT-GUANO localization skymap of a long GRB
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39672 SUBJECT: GRB 250226A: Swift/BAT-GUANO localization skymap of a long GRB DATE: 25/03/11 20:10:44 GMT FROM: Samuele Ronchini at PSU <sjs8171(a)psu.edu> Samuele Ronchini (PSU), James DeLaunay (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 250226A onboard (T0: 2025-02-26T06:34:57.33 UTC, Fermi GCN 39479, GECAM GCN 39492, EP-WXT GCN 39482, INTEGRAL … [View More]GCN 39518) The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 23.9 in a 8.192 s analysis time bin, starting at T0. Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2025. in prep) The 90% credible area is 1,797 deg2 and the 50% credible area is 312 deg2. The integrated probability inside the coded field of view is <1%. The joint NITRATES+GBM localization has a 90% credible area of 178 deg2 and a 50% credible area of 51 deg2, and is consistent with the external position by EP-WXT (GCN 39482) A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=762244532/#:~:te… The probability skymap and joint skymap files can be downloaded from the links here [skymap_fits_file](https://guano.swift.psu.edu/files/762244532/0_n_PROBMAP) [joint_skymap_fits_file](https://guano.swift.psu.edu/files/762244532/0_n_JOI… Instructions on how to read and manipulate this map can be found here: https://guano.swift.psu.edu/documentation More details about this burst can be found on the trigger report page here: https://guano.swift.psu.edu/trigger_report?id=762244532 GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/ View this GCN Circular online at https://gcn.nasa.gov/circulars/39672. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37687] GRB 250223B: Swift/BAT-GUANO localization skymap of a short burst
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39671 SUBJECT: GRB 250223B: Swift/BAT-GUANO localization skymap of a short burst DATE: 25/03/11 20:10:42 GMT FROM: Samuele Ronchini at PSU <sjs8171(a)psu.edu> James DeLaunay (PSU), Samuele Ronchini (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 250223B onboard (T0: 2025-02-23T10:19:23.76 UTC, Fermi trig 762615997) The Fermi notice, distributed in … [View More]near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 17.3 in a 16.384 s analysis time bin, starting at T0 - 4.096 s. Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2025. in prep) The 90% credible area is 2,445 deg2 and the 50% credible area is 462 deg2. The integrated probability inside the coded field of view is <1%. The NITRATES skymap is consistent with the Fermi localization reported in the final position notice (GCN 39435). The combined Fermi/GBM+NITRATES 90% credible area is 152 deg2 and the 50% credible area is 46 deg2. A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=762616028/#:~:te… The probability skymap and joint skymap files can be downloaded from the links here [skymap_fits_file](https://guano.swift.psu.edu/files/762616028/0_n_PROBMAP) [joint_skymap_fits_file](https://guano.swift.psu.edu/files/762616028/0_n_JOI… Instructions on how to read and manipulate this map can be found here: https://guano.swift.psu.edu/documentation More details about this burst can be found on the trigger report page here: https://guano.swift.psu.edu/trigger_report?id=762616028 GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/ View this GCN Circular online at https://gcn.nasa.gov/circulars/39671. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37686] GRB 250309B: PRIME near-infrared detection
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39670 SUBJECT: GRB 250309B: PRIME near-infrared detection DATE: 25/03/11 19:46:22 GMT FROM: O. Guiffreda at UMD <oriogui(a)umd.edu> GRB 250309B: PRIME near-infrared detection O. Guiffreda (UMD), J. Durbak (UMD), E. Troja (U Rome), A. S. Kutyrev (NASA/GSFC), S. B. Cenko (NASA/GSFC) Following the Fermi GBM trigger (GCN 39635), we observed the transient field in J and H filters with PRIME ~1.5 days after the Fermi detection. At the position of the … [View More]

1 0

[vsnet-grb-info 37685] EP250304a: Chandra detection
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39669 SUBJECT: EP250304a: Chandra detection DATE: 25/03/11 18:08:57 GMT FROM: Raffaella Margutti <rmargutti(a)berkeley.edu> R. Margutti (UC Berkeley), S. Pedrami (UC Berkeley), R. Chornock (UC Berkeley), Y. Yao (UC Berkeley), T. Laskar (U of Utah) report: We observed EP250304a (Chen et al., GCN 39580) with the Chandra X-ray Observatory starting on 2025-03-10, 03:13:38 UT (i.e., T0+6.2d, observer frame; 20ks exposure) under a DDT proposal (PI … [View More]

1 0

[vsnet-grb-info 37684] GRB 250225B: Swift-BAT refined analysis
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39668 SUBJECT: GRB 250225B: Swift-BAT refined analysis DATE: 25/03/11 18:05:56 GMT FROM: Rahul Gupta at NASA GSFC <rahul.gupta(a)nasa.gov> T. Sakamoto (AGU), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), M. A. Williams (PSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+… [View More]

1 0

[vsnet-grb-info 37683] GRB 250311A/EP250311a: TRT optical upper limit
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39667 SUBJECT: GRB 250311A/EP250311a: TRT optical upper limit DATE: 25/03/11 12:48:25 GMT FROM: Wenxiong Li at NAOC <liwenxiong1992(a)gmail.com> W.X. Li (NAOC), S. Tinyanont, R. Anutarawiramkul, P. Butpan (NARIT), N.C. Sun, D. Xu, Z. Fan, Y.N. Wang (NAOC), report on behalf of a large collaboration: We observed the field of GRB 250311A/EP250311a detected by MAXI (Tatano et al. GCN 39660) and EP (Mao et al., GCN 39664), using the 0.7-m telescope of … [View More]

1 0

[vsnet-grb-info 37682] IceCube-250309A: MITSuME Akeno and Seimei/TriCCS optical observations
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39666 SUBJECT: IceCube-250309A: MITSuME Akeno and Seimei/TriCCS optical observations DATE: 25/03/11 11:59:31 GMT FROM: Ichiro Takahashi at Science Tokyo <itakahashi(a)hp.phys.titech.ac.jp> Ichiro Takahashi (Science Tokyo), Kenta Taguchi (Kyoto U.), Seiji Toshikage, Masaomi Tanaka (Tohoku U.), Yousuke Utsumi (NAOJ), Ryosuke Itoh (Ibara City), Tomoki Morokuma (ARC/Chitech) report on behalf of a larger collaboration: We performed optical imaging … [View More]

1 0

[vsnet-grb-info 37681] GRB 250311A: Tiled Swift observations
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39665 SUBJECT: GRB 250311A: Tiled Swift observations DATE: 25/03/11 11:30:09 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a series of observations, tiled on the sky, of the MAXI GRB 250311A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00135 Any uncatalogued X-ray sources detected in … [View More]

1 0

[vsnet-grb-info 37680] EP250311a/GRB 250311A: EP-WXT detection
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39664 SUBJECT: EP250311a/GRB 250311A: EP-WXT detection DATE: 25/03/11 10:28:02 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> X. Mao (NAO, CAS), Y. J. Zhang (THU), Y. L. Hua (PMO, CAS), Z. X. Ling (NAO, CAS) report on behalf of the Einstein Probe team: We report on the detection of a fast X-ray transient EP250311a at 2025-03-11T01:56:19 (UTC) by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission. The position of the … [View More]

1 0

[vsnet-grb-info 37679] GRB 250308A: CALET Gamma-Ray Burst Monitor detection
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39663 SUBJECT: GRB 250308A: CALET Gamma-Ray Burst Monitor detection DATE: 25/03/11 09:19:04 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo(a)phys.aoyama.ac.jp> Y. Kawakubo, A. Yoshida, T. Sakamoto, S. Sugita (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. … [View More]

1 0

[vsnet-grb-info 37678] GRB 250311B: SVOM detection of a burst
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39662 SUBJECT: GRB 250311B: SVOM detection of a burst DATE: 25/03/11 08:25:41 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> C.W. Wang (IHEP), R.C. Chen (NJU), H. Goto, D. Turpin (CEA), M. G. Bernardini (INAF-OAB, LUPM) on behalf of the SVOM mission team. At 2025-03-11T07:08:05.065 UTC (Tb) SVOM/ECLAIRs triggered on the gamma-ray burst GRB 250311B (SVOM burst-id sb25031101). The following trigger information was received on the ground with low … [View More]

1 0

[vsnet-grb-info 37677] GRB 250309B: SVOM/VT optical observation
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39661 SUBJECT: GRB 250309B: SVOM/VT optical observation DATE: 25/03/11 06:47:44 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> Z. M. Wang, A. Li (BNU), Y. F. Liang (PMO), L. P. Xin, Y. L. Qiu, H. L. Li, Z. H. Yao, Y. Xu, P. P. Zhang, W. J. Xie, J. Wang, X. H. Han, Y. J. Xiao, H. B. Cai, J. Y. Wei (NAOC), J. T. Palmerio (CEA/Irfu) report on behalf of the SVOM team: The SVOM/VT conducted a ToO follow-up observation of ZTF25aaitvjt / AT2025dws (Stein et … [View More]

1 0

[vsnet-grb-info 37676] GRB 250311A/MAXI J1457-026: MAXI/GSC detection
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39660 SUBJECT: GRB 250311A/MAXI J1457-026: MAXI/GSC detection DATE: 25/03/11 03:47:32 GMT FROM: Yuta Kawakubo at Aoyama Gakuin University <kawakubo(a)phys.aoyama.ac.jp> K. Tatano, H. Negoro, M. Nakajima (Nihon U.), M. Serino, Y. Kawakubo (AGU), Y. Kudo, H. Shibui, K. Takagi, H. Takahashi, H. Nishio (Nihon U.), T. Mihara, S. Yamada, S. Wang, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN), T. Sakamoto, S. Sugita, H. Hiramatsu, H. Nishikawa, Y. Kondo, S. … [View More]Sasao, A. Yoshida (AGU), Y. Tsuboi, H. Sugai, N. Nagashima (Chuo U.), M. Shidatsu, Y. Niida (Ehime U.), I. Takahashi, M. Niwano, N. Higuchi, Y. Yatsu (Tokyo Tech), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, M. Kurihara (JAXA), Y. Ueda, Y. Okada, K. Fujiwara (Kyoto U.), M. Yamauchi, Y. Otsuki, T. Hasegawa, M. Nishio (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Sugizaki (Kanazawa U.), W. Iwakiri (Chiba U.), T. Kawamuro (Osaka U.) report on behalf of the MAXI team: The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 01:55:22 UT on March 11, 2025. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (224.318 deg, -2.613 deg) = (14 57 16, -02 36 46) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.33 deg and 0.28 deg, respectively. The roll angle of long axis from the north direction is 9.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 75 +- 18 mCrab (4.0-10.0keV, 1 sigma error). Without assumptions on the source constancy, we obtain a rectangular error box for the transient source with the following corners: (223.607, -1.537) deg = (14 54 25, -01 32 13) (J2000) (223.164, -1.982) deg = (14 52 39, -01 58 55) (J2000) (225.099, -3.901) deg = (15 00 23, -03 54 03) (J2000) (225.542, -3.455) deg = (15 02 10, -03 27 18) (J2000) There was no significant excess flux in the previous transit at 00:22 UT and in the next transit at 03:28 UT with an upper limit of 20 mCrab for each. We note that the source position is consistent with the position of GRB 250305A reported by Fermi-GBM (#39597). We encourage follow-up observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/39660. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37675] The EP-WXT trigger 01709132425 is not a real source
by GCN Circulars 11 Mar '25

11 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39659 SUBJECT: The EP-WXT trigger 01709132425 is not a real source DATE: 25/03/11 02:14:26 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y.L. Hua (PMO), Y. J. Zhang (THU), X. Mao, Z. X. Ling (NAO, CAS) report on behalf of the Einstein Probe team: Further analysis of the data suggests that the EP-WXT on-board trigger (ID: 01709132425) at 2025-03-10 18:42:15 (UTC) is not a real source. Launched on January 9, 2024, EP is a space X-ray observatory … [View More]

1 0

[vsnet-grb-info 37674] GRB 250309B / AT2025dws: further SAO RAS optical observations
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39658 SUBJECT: GRB 250309B / AT2025dws: further SAO RAS optical observations DATE: 25/03/10 23:50:28 GMT FROM: Alexander Moskvitin at SAO RAS <mosk(a)sao.ru> A. S. Moskvitin, O. I. Spiridonova (SAO RAS), A. S. Pozanenko (IKI), A. Ghosh, S. Razzaque (CAPP, University of Johannesburg), Yu. V. Sotnikova (SAO RAS) report on behalf of a larger collaboration. We observed the field of GRB 250309B / AT2025dws (Preis and Greiner, GCN 39629; Fermi GBM team, … [View More]

1 0

[vsnet-grb-info 37673] IceCube-250309A: Upper limits from Fermi-GBM Observations
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39657 SUBJECT: IceCube-250309A: Upper limits from Fermi-GBM Observations DATE: 25/03/10 23:19:19 GMT FROM: Lorenzo Scotton at UAH <lscottongcn(a)outlook.com> L. Scotton (UAH) reports on behalf of the Fermi-GBM Team: For the IceCube high-energy neutrino candidate event IceCube-250309A (GCN 39631), at the event time Fermi-GBM was observing the reported neutrino location at: RA: 211.07 (+0.31 -0.30 deg 90% PSF containment) J2000 Dec: -10.73 (+0.26 -0.… [View More]

1 0

[vsnet-grb-info 37672] EP250308a: 1.6m Mephisto optical upper limits
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39656 SUBJECT: EP250308a: 1.6m Mephisto optical upper limits DATE: 25/03/10 17:46:43 GMT FROM: Brajesh Kumar at SWIFAR, YNU <brajesh(a)ynu.edu.cn> Shiyan Zhong, Jinghua Zhang, Guowang Du, Xin Chang, Bin Yan, Xingzhu Zou, Brajesh Kumar, Yuan Fang, Helong Guo, Edoardo P. Lagioia, Yuanpei Yang, Xiangkun Liu, Xiaowei Liu (all SWIFAR, YNU) report on behalf of the Mephisto Team: The field of EP250308a (Yin et al., GCN 39625) was observed with the 1.6m … [View More]

1 0

[vsnet-grb-info 37671] Konus-Wind detection of GRB 250309B
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39655 SUBJECT: Konus-Wind detection of GRB 250309B DATE: 25/03/10 17:17:33 GMT FROM: Dmitry Frederiks at Ioffe Institute <fred(a)mail.ioffe.ru> D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 250309B ( Fermi-GBM BALROG localization: Preis and Greiner, GCN 39629; Fermi-GBM detection: The Fermi GBM team, GCN 39635; McDermott et al., GCN 39642; GECAM-… [View More]B detection: Wang et al., GCN 39648; IPN triangulation: Kozyrev et al., GCN 39652) triggered Konus-Wind (KW) at T0=27513.791 s UT (07:38:33.791). The burst light curve shows a multi-peaked structure which starts at ~T0-0.5 s and has a total duration of ~8 s. The emission is seen up to ~1 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB250309_T27513/ As observed by Konus-Wind, the burst had a fluence of (5.79 ± 0.48)x10^-6 erg/cm^2 and a 64-ms peak energy flux, measured from T0 + 1.024 s, of (4.35 ± 0.43)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by a power law with exponential cutoff (CPL) model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.03(-0.20,+0.22) and Ep = 106(-7,+8) keV (chi2 = 80/79 dof). Fitting this spectrum by a Band function yields the same values of alpha and Ep, and an upper limit on the high energy photon index beta of -3.1 (chi2 = 79/78 dof). Assuming the redshift z=1.898 ( Malesani et al., GCN 39647) of ZTF25aaitvjt/AT 2025dws, the candidate counterpart to GRB 250309B (Stein et al., GCN 39639), and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014), we estimate the burst isotropic energy release E_iso to (5.3 ± 0.4)x10^52 erg, the isotropic peak luminosity L_iso to (1.2 ± 0.12)x10^53 erg/s, and the rest-frame peak spectral energy Ep,z to (306 ± 21) keV. With the obtained estimates, GRB 250309B is consistent with 68% prediction band of the 'Amati' relation and 90% prediction band of the 'Yonetoku' relation for the sample of >300 long KW GRBs with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021), see http://www.ioffe.ru/LEA/GRBs/GRB250309_T27513/GRB250309B_rest_frame.pdf All the quoted errors are estimated at the 68% confidence level. All the presented results are preliminary. View this GCN Circular online at https://gcn.nasa.gov/circulars/39655. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37670] GRB 250309B / AT2025dws: KMTNet-CTIO optical observations
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39654 SUBJECT: GRB 250309B / AT2025dws: KMTNet-CTIO optical observations DATE: 25/03/10 16:46:17 GMT FROM: Min-Su Shin at Korea Astronomy and Space Science Institute <msshin(a)kasi.re.kr> Min-Su Shin (Korea Astronomy and Space Science Institute; KASI), Jae-Woo Kim (KASI), and Seo-Won Chang (Seoul National University) report on behalf of the KMTNet neutrino ToO program: … [View More]

1 0

[vsnet-grb-info 37669] IPN triangulation of GRB 250308A (short)
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39653 SUBJECT: IPN triangulation of GRB 250308A (short) DATE: 25/03/10 16:02:51 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars Odyssey team, D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, Y. Zhang, C. Wang, S. Xiong, J. Wei, and B. Cordier on behalf of the SVOM-GRM team, S. … [View More]

1 0

[vsnet-grb-info 37668] IPN triangulation of GRB 250309B
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39652 SUBJECT: IPN triangulation of GRB 250309B DATE: 25/03/10 13:17:34 GMT FROM: Dmitry Svinkin at Ioffe Institute <svinkin(a)mail.ioffe.ru> A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the HEND/Mars Odyssey team, D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM team, and W. … [View More]

1 0

[vsnet-grb-info 37667] IceCube-241224A: MASTER detection of PKS 1217+02 blazar flare with Zhirkov effect
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39651 SUBJECT: IceCube-241224A: MASTER detection of PKS 1217+02 blazar flare with Zhirkov effect DATE: 25/03/10 12:01:17 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> K. Labzina, K.Zhirkov, V.Lipunov, E.Gorbovskoy, A.Kuznetsov, G.Antipov, D.Vlasenko, A.Kuznetsov, N.Tyurina, P.Balanutsa, A.Chasovnikov, V.Topolev, Ya.Kechin, V.Senik, Yu.Tselik (Lomonosov MSU), O.Gress, N.Budnev, O.Ershova (ISU), C.Francile, F. … [View More]

1 0

[vsnet-grb-info 37666] GRB 250309B/AT2025dws : COLIBRÍ Detection of the Optical Counterpart
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39650 SUBJECT: GRB 250309B/AT2025dws : COLIBRÍ Detection of the Optical Counterpart DATE: 25/03/10 11:48:47 GMT FROM: F. Fortin at IRAP <ffortin.sci.edu(a)gmail.com> Jean-Grégoire Ducoin (CPPM), Francis Fortin (IRAP), Kin Ocelotl López (UNAM), Francesco Magnani (CPPM), Stéphane Basa (UAR Pytheas), Benjamin Schneider (LAM), Alan M. Watson (UNAM), William H. Lee (UNAM), Camila Angulo (UNAM), Dalya Akl (AUS), Sarah Antier (OCA), Jean-Luc Atteia (IRAP), … [View More]

1 0

[vsnet-grb-info 37665] GRB 250309B: Swift-XRT refined Analysis
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39649 SUBJECT: GRB 250309B: Swift-XRT refined Analysis DATE: 25/03/10 07:19:06 GMT FROM: K.L. Page at U Leicester <klp5(a)leicester.ac.uk> K.L. Page and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 3.9 ks of XRT data for the Fermi/GBM-detected GRB 250309B, from 46.1 to 57.7 ks after the Fermi trigger (GCN Circs. 39635, 39642). The data are entirely in Photon Counting (PC) mode. We detect a previously uncatalogued X-ray source … [View More]

1 0

[vsnet-grb-info 37664] GRB 250309B / IceCube-250309A: GECAM-B observations
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39648 SUBJECT: GRB 250309B / IceCube-250309A: GECAM-B observations DATE: 25/03/10 07:04:11 GMT FROM: Yue Wang <m18509381757(a)163.com> Yue Wang, Jia-Cong Liu, Jin-Peng Zhang, Chen-Wei Wang, Wen-Jun Tan, Wang-Chen Xue, Shao-Lin Xiong (IHEP), report on behalf of the GECAM team: GECAM-B was triggered on-ground by a long burst, GRB 250309B, at 2025-03-09T07:38:31.050 UTC (T0), which was also observed by Fermi/GBM (McDermott et al., GCN 39642). … [View More]According to GECAM-B light curve, this burst mainly consists of multiple pulses with a duration (T90) of about 6.74 (+/-0.15) sec (50-300 keV). The GECAM-B light curve of GRB 250309B could be found at: https://www.bursthub.cn//admin/static/gecamgrb250309B.png The GECAM-B localization of GRB 250309B is consistent with the Fermi/GBM localization of this burst (McDermott et al., GCN 39642) and the position of optical counterpart AT 2025dws (Stein et al., GCN 39639) as well as the IceCube-250309A (The IceCube Collaboration, GCN 39631). Thus, we confirm that GRB 250309B is spatially and temporally coincident with IceCube-250309A. The time-integrated spectrum of GRB 250309B from T0-1.0 s to T0+6.0 s is best fitted by a cutoff-powerlaw function with Epeak = 109.3 +/- 6.8 keV and alpha = -1.00 +/- 0.27. The event fluence (10-1000 keV) in this time interval is (7.65 +/- 0.56)E-06 erg/cm^2. With the measured redshift z=1.898 (D. B. Malesani et al., GCN 39647), we calculate the isotropic energy Eiso is (7.4 ± 0.8)x10^52 erg. Then we note that GRB 250309B is well consistent with Type II GRBs in the 'Amati' relation diagram, as shown at: https://www.bursthub.cn//admin/static/grb250309B_amati.png Further, we note that there is no GECAM-B trigger just around the event time of IceCube-250309A (2025-03-09 at 07:36:04.75 UT, The IceCube Collaboration, GCN 39631). We implemented a targeted search [1] for burst activities from T0-330 s to T0-30 s embracing this IceCube event, but identified no candidate above 3 sigma. Thus, we calculated the upper limit of a potential precursor of GRB 250309B which is simultaneously associated with IceCube-250309A. Considering three typical GRB spectral models (i.e. soft, normal and hard Band functions), three timescales and the center region of GRB localization (RA= 211.07, Dec = -10.73), the 3 sigma upper limits of the potential GRB precursor energy flux (15 keV-5000 keV, in units of 10^-7 erg/s/cm^2) are reported below: |Timescale (s)|Soft|Normal|Hard| | ------------ | ------------ | ------------ | ------------ | |0.1|3.86|3.92|6.33| |1 |1.22|1.24|2.00| |10 |0.38|0.39|0.63| We note that these results are preliminary. Refined analysis will be reported. Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS). View this GCN Circular online at https://gcn.nasa.gov/circulars/39648. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37663] GRB 250309B / AT2025dws: OSIRIS+/GTC spectroscopy z=1.898
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39647 SUBJECT: GRB 250309B / AT2025dws: OSIRIS+/GTC spectroscopy z=1.898 DATE: 25/03/10 05:47:31 GMT FROM: Antonio de Ugarte Postigo at LAM, CNRS <adeugartepostigo(a)gmail.com> D. B. Malesani (DAWN/NBI and Radboud Univ.), A. de Ugarte Postigo (LAM), A. Martin-Carrillo (UCD), C. C. Thoene (AbAO), J. F. Agui Fernandez (CAHA), N. R. Tanvir (Univ. Leicester), L. Izzo (INAF/OACn and DARK/NBI), J. P. U. Fynbo (DAWN/NBI), S. Geier (GTC), G. Lombardi (GTC), … [View More]

1 0

[vsnet-grb-info 37662] Liverpool Telecope observations of AT 2025dws / GRB 250309B
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39646 SUBJECT: Liverpool Telecope observations of AT 2025dws / GRB 250309B DATE: 25/03/10 03:52:06 GMT FROM: Daniel Perley at Liverpool JMU <d.a.perley(a)ljmu.ac.uk> D. A. Perley (LJMU), A. Bochenek (LJMU), and A. Y. Q. Ho (Cornell) report: We obtained imaging observations of AT2025dws (Stein et al., GCN 39639), a possible optical counterpart of GRB 250309B (Preis & Greiner, GCN 39629; McDermott et al., GCN 39635) with IO:O on the Liverpool … [View More]

1 0

[vsnet-grb-info 37661] GRB 250309B / AT2025dws: SAO RAS optical observations
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39645 SUBJECT: GRB 250309B / AT2025dws: SAO RAS optical observations DATE: 25/03/10 02:45:01 GMT FROM: Moskvitin Alexander at SAO RAS <mosk(a)sao.ru> A. S. Moskvitin, O. I. Spiridonova (SAO RAS), A. S. Pozanenko (IKI), A. Ghosh, S. Razzaque (CAPP, University of Johannesburg), Yu. V. Sotnikova (SAO RAS) report on behalf of a larger collaboration. We partially covered the error circle of the GRB 250309B (Preis and Greiner, GCN 39629; Fermi GBM team, … [View More]

1 0

[vsnet-grb-info 37660] GRB 250309B / AT2025dws: Swift-UVOT detection
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39644 SUBJECT: GRB 250309B / AT2025dws: Swift-UVOT detection DATE: 25/03/10 02:12:00 GMT FROM: Robert David Stein at JSI <rdstein(a)umd.edu> Robert Stein (JSI), Tomas Ahumada (Caltech) report, On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations: We requested observations of AT2025dws (Stein et al., GCN 39639), the candidate counterpart to GRB 250309B (Preis & … [View More]

1 0

[vsnet-grb-info 37659] AT 2025dws, likely optical counterpart of GRB 250309B: LCO confirmation of fast fading
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39643 SUBJECT: AT 2025dws, likely optical counterpart of GRB 250309B: LCO confirmation of fast fading DATE: 25/03/10 01:28:25 GMT FROM: Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf(a)iac.es> I. Pérez-Fournon, F. Poidevin (IAC and ULL), D. Cano-Morales, I. Correa-Plasencia, and A.E. Hernández-Díaz (ULL) We report Las Cumbres Observatory Global Telescope network (LCOGT) observations of ZTF25aaitvjt / AT 2025dws, that has been … [View More]

1 0

[vsnet-grb-info 37658] GRB 250309B: Fermi GBM Observation
by GCN Circulars 10 Mar '25

10 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39642 SUBJECT: GRB 250309B: Fermi GBM Observation DATE: 25/03/10 00:47:24 GMT FROM: Lorenzo Scotton at UAH <lscottongcn(a)outlook.com> P. McDermott (UCD), P. Veres (UAH) and L. Scotton (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 07:38:30.66 UT on 09 March 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250309B (trigger 763198715/250309318). The Fermi GBM on-ground location was reported in GCN 39635. … [View More]

1 0

[vsnet-grb-info 37657] Fermi GRB 250309B: Global MASTER-Net observations report
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39641 SUBJECT: Fermi GRB 250309B: Global MASTER-Net observations report DATE: 25/03/09 22:31:38 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta,… [View More]

1 0

[vsnet-grb-info 37656] Fermi GRB 250309A: Global MASTER-Net observations report
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39640 SUBJECT: Fermi GRB 250309A: Global MASTER-Net observations report DATE: 25/03/09 22:31:05 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta,… [View More] R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 250309A ( Fermi GBM team, GCN 39623) errorbox 71845 sec after notice time and 71879 sec after trigger time at 2025-03-09 20:40:03 UT, with upper limit up to 16.2 mag. The observations began at zenith distance = 81 deg. The sun altitude is -50.2 deg. The galactic latitude b = 0 deg., longitude l = 140 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2805313 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 71900 | 2025-03-09 20:40:03 | MASTER-Kislovodsk | (02h 47m 28.83s , +38d 43m 03.4s) | C | 40 | 15.5 | 71955 | 2025-03-09 20:40:03 | MASTER-Kislovodsk | (02h 47m 28.84s , +38d 43m 03.3s) | C | 150 | 16.2 | Coadd 71965 | 2025-03-09 20:41:03 | MASTER-Kislovodsk | (02h 47m 28.70s , +38d 42m 52.8s) | C | 50 | 15.4 | 72040 | 2025-03-09 20:42:13 | MASTER-Kislovodsk | (02h 47m 28.63s , +38d 42m 43.8s) | C | 60 | 15.6 | 72130 | 2025-03-09 20:43:33 | MASTER-Kislovodsk | (02h 47m 28.55s , +38d 42m 35.0s) | C | 80 | 15.7 | 72240 | 2025-03-09 20:43:33 | MASTER-Kislovodsk | (02h 47m 28.54s , +38d 42m 34.9s) | C | 300 | 16.1 | Coadd 72240 | 2025-03-09 20:45:13 | MASTER-Kislovodsk | (02h 47m 28.42s , +38d 42m 25.5s) | C | 100 | 15.8 | 72370 | 2025-03-09 20:47:13 | MASTER-Kislovodsk | (02h 47m 28.29s , +38d 42m 16.6s) | C | 120 | 15.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/39640. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37655] GRB250309B: One candidate counterpart from the Zwicky Transient Facility
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39639 SUBJECT: GRB250309B: One candidate counterpart from the Zwicky Transient Facility DATE: 25/03/09 18:25:09 GMT FROM: Robert David Stein at JSI <rdstein(a)umd.edu> Robert Stein (JSI), Tomas Ahumada (Caltech), Jannis Necker, Akshay Eranhalodi (DESY), and Anna Franckowiak (Ruhr University Bochum), Jesper Sollerman (Stockholm) report: On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (… [View More]GROWTH) collaborations: We observed the localisation of Gamma-Ray Burst GRB 250309B (McDermott et al., GCN 39635) with the Palomar 48-inch telescope equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). This GRB was reported to be in spatial/temporal coincidence with high-energy neutrino IC250309A (Zegarelli et. al, GCN 39631), and our observations included ToO observations (Stein et al., GCN 39638) conducted as part of the ZTF neutrino follow up program (Stein et al. 2023). We started serendiptious observations of the GRB skymap in the g- and r-band beginning at 2025-03-09 07:51 UTC, approximately 0.3 hours after event time. We covered 80% of the reported localization region. This estimate accounts for chip gaps. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019, Stein et al. 2021) was used to search the alerts database for candidates. We reject stellar sources (Tachibana and Miller 2018) and moving objects, and apply machine learning algorithms (Mahabal et al. 2019). After applying standard candidate vetting procedures, we identified the following candidate optical afterglow: ±–––––––––––––––––––––––––––––––––––––––-+ | ZTF Name | IAU Name | RA (deg) | DEC (deg) | Filter | Mag | MagErr | ±–––––––––––––––––––––––––––––––––––––––-+ | ZTF25aaitvjt | AT2025dws | 210.801761 | -8.502842 | r | 18.48| 0.107 | ±–––––––––––––––––––––––––––––––––––––––-+ Using the smaller BALROG localisation (Greiner et al, GCN 39629), we covered 76.8% (1.9 sq deg) of the reported localization region. This estimate accounts for chip gaps. Repeating the same search, AT2025dws is again the only candidate found within the error contour of the GRB. AT2025dws is red (g−r>0.4 mag) and is coincident with a faint Legacy Survey source that appears to be a possible host galaxy. From the ATLAS forced photometry service, we find that the transient had deeper upper limit (m>19.2) 1.67 hours before the GRB trigger. This suggests that AT2025dws is both fast-evolving, and temporally coincident with the GRB. Given this, we consider AT2025dws to be the likely afterglow counterpart. We encourage spectroscopic observations to confirm the nature of AT2025dws as an afterglow. ToO observations have been requested with the Neil Gehrels Swift Observatory. We note that none of ZTF25aaitvjt/AT2025dws is located 2.24 degrees from the center of the neutrino localisation. If this is indeed the afterglow, then the offset to the reported neutrino uncertainty region is >5 sigma, suggesting that the neutrino and GRB are not associated. We will continue to observe this field as part of our standard ToO cadence for high-energy neutrinos (Stein et al. 2023). Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Award #2407588 and a partnership including Caltech, USA; Caltech/IPAC, USA; University of Maryland, USA; University of California, Berkeley, USA; University of Wisconsin at Milwaukee, USA; Cornell University, USA; Drexel University, USA; University of North Carolina at Chapel Hill, USA; Institute of Science and Technology, Austria; National Central University, Taiwan; Operations are conducted by Caltech's Optical Observatory (COO), Caltech/IPAC, and the University of Washington at Seattle, USA. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019). Alert filtering is performed with the nuztf (Stein et al. 2021, https://github.com/desy-multimessenger/nuztf ). View this GCN Circular online at https://gcn.nasa.gov/circulars/39639. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37654] IceCube-250309A: No candidates from the Zwicky Transient Facility
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39638 SUBJECT: IceCube-250309A: No candidates from the Zwicky Transient Facility DATE: 25/03/09 18:24:08 GMT FROM: Robert David Stein at JSI <rdstein(a)umd.edu> Robert Stein (JSI), Jannis Necker, Akshay Eranhalodi (DESY), and Anna Franckowiak (Ruhr University Bochum), Tomas Ahumada (Caltech), Jesper Sollerman (Stockholm) report: On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) … [View More]collaborations: As part of the ZTF neutrino follow up program (Stein et al. 2023), we observed the localization region of the neutrino event IceCube-250309A (Zegarelli et. al, GCN 39631) with the Palomar 48-inch telescope, equipped with the 47 square degree ZTF camera (Bellm et al. 2019, Graham et al. 2019). We started deep observations in the g- and r-band beginning at 2025-03-09 10:16 UTC while the same field was also observed by the routine ZTF survey at 08:18 UTC, approximately 0.7 hours after event time. We covered 92.9% (0.3 sq deg) of the reported localization region. This estimate accounts for chip gaps. Each exposure was 300s with a typical depth of 21.0 mag. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC to search for potential counterparts (Masci et al. 2019). AMPEL (Nordin et al. 2019, Stein et al. 2021) was used to search the alerts database for candidates. We reject stellar sources (Tachibana and Miller 2018) and moving objects, and apply machine learning algorithms (Mahabal et al. 2019). We are left with one candidate within the 90.0% localization of the skymap. ±–––––––––––––––––––––––––––––––––––––––-+ | ZTF Name | IAU Name | RA (deg) | DEC (deg) | Filter | Mag | MagErr | ±–––––––––––––––––––––––––––––––––––––––-+ | ZTF25aaiurnn | –––- | 211.3537073 | -10.4938701 | g | 20.82 | 0.18 | ±–––––––––––––––––––––––––––––––––––––––-+ ZTF25aaiurnn was first detected on 2025-03-02 in the r-band, roughly one week before the neutrino arrival. It has a match in the MILLIQUAS catalog at a distance of 0.18 arcsec as a 95% probable QSO. The match in the AllWISE source catalog (WISEA J140524.90-102938.0, 0.22 arcsec) shows a red color of W1-W2=1), consistent with an AGN. Although there is only one detection per band, there is no clear evidence for coincident flaring activity. We will continue to observe this field as part of our standard ToO cadence for high-energy neutrinos (Stein et al. 2023). Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Award #2407588 and a partnership including Caltech, USA; Caltech/IPAC, USA; University of Maryland, USA; University of California, Berkeley, USA; University of Wisconsin at Milwaukee, USA; Cornell University, USA; Drexel University, USA; University of North Carolina at Chapel Hill, USA; Institute of Science and Technology, Austria; National Central University, Taiwan; Operations are conducted by Caltech's Optical Observatory (COO), Caltech/IPAC, and the University of Washington at Seattle, USA. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019). Alert database searches are done by AMPEL (Nordin et al. 2019). Alert filtering is performed with the nuztf (Stein et al. 2021, https://github.com/desy-multimessenger/nuztf ). View this GCN Circular online at https://gcn.nasa.gov/circulars/39638. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37653] Fermi-LAT gamma-ray observations of IceCube-250309A
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39637 SUBJECT: Fermi-LAT gamma-ray observations of IceCube-250309A DATE: 25/03/09 17:38:48 GMT FROM: Sara Buson at DESY, Univ. of Wurzburg <sara.buson(a)gmail.com> S. Buson (DESY, Univ. of Wuerzburg), S. Garrappa (Weizmann Institute of Science), L. Pfeiffer (Univ. of Wuerzburg), N. Di Lalla (Stanford Univ.), M. Arimoto (Kanazawa University), R. Gupta (NASA GSFC) and A. Holzmann Airasca (UniTrento and INFN Bari) on behalf of the Fermi-LAT … [View More]collaboration: We report an analysis of observations of the vicinity of the high-energy IC250309A neutrino event (GCN 39631) with all-sky survey data from the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. The IceCube event was detected on 2025-03-09 07:36:04.75 UTC (T0) with J2000 position RA = 211.07 (+0.31, -0.30) deg, Decl. = -10.73 (+0.26, -0.30) deg 90% PSF containment. No cataloged gamma-ray sources are found within the 90% IC250309A localization error (The Fourth Fermi-LAT catalog, 4FGL-DR4, The Fermi-LAT collaboration 2023, arXiv:2307.12546). We searched for the existence of intermediate (days to years) timescale emission from a new gamma-ray transient source. Preliminary analysis indicates no significant (>5sigma) new excess emission (> 100 MeV) within the IC250309A 90% confidence localization. Assuming a power-law spectrum (photon index = 2.0 fixed) for a point source at the IceCube best-fit position, the >100 MeV flux upper limit (95% confidence) is <2.4e-10 ph cm^-2 s^-1 for ~16-years (2008-08-04 / T0), <6.8e-09 (<9.3 e-8) ph cm^-2 s^-1 for a 1-month (1-day) integration time before T0. The IceCube event IC250309A occurred near the GRB 250309B (GCN 39635), with a detection time 145.91 seconds after the Fermi-GBM trigger and a positional separation of 0.50 deg. An analysis of the LAT data conducted over a ±1000-second window centered on T0, shows no significant excess emission, neither associated with IC250309A nor GRB 250309B. The >100 MeV flux upper limit (95% confidence) at IC250309A best-fit position for this time interval is < 5.3 e-6 ph cm^-2 s^-1. Since Fermi normally operates in an all-sky scanning mode, regular monitoring of this source will continue. For this source, the Fermi-LAT contact person is S. Buson (sara.buson at uni-wuerzburg.de). The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. View this GCN Circular online at https://gcn.nasa.gov/circulars/39637. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37652] GRB 250308A: SVOM/GRM detection of QPO in the tail emission
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39636 SUBJECT: GRB 250308A: SVOM/GRM detection of QPO in the tail emission DATE: 25/03/09 16:00:23 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> SVOM/GRM team: Chen-Wei Wang, Wen-Jun Tan, Zheng-Hang Yu, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Nicolas Dagoneau (CEA), Maria-Grazia Bernardini (INAF-OAB), Jean-Luc Atteia (IRAP), Frédéric Piron (LUPM) Report on behalf of the SVOM team: The bright short … [View More]

1 0

[vsnet-grb-info 37651] GRB 250309B: Fermi GBM Final Localization
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39635 SUBJECT: GRB 250309B: Fermi GBM Final Localization DATE: 25/03/09 15:47:40 GMT FROM: Padraig McDermott at University College Dublin <padraig.mcdermott(a)ucdconnect.ie> The Fermi GBM team reports the detection of a likely LONG GRB "At 07:38:30.66 UT on 09 March 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250309B (trigger 763198715/250309318). The on-ground calculated location, using the Fermi GBM trigger data, is RA =… [View More]

1 0

[vsnet-grb-info 37650] Correction to GCN 39633 - Swift is observing GRB 250309B/IceCube-250309A!
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39634 SUBJECT: Correction to GCN 39633 - Swift is observing GRB 250309B/IceCube-250309A! DATE: 25/03/09 13:20:55 GMT FROM: P.A. Evans at U. Leicester <pae9(a)leicester.ac.uk> P.A. Evans reports on behalf of the Swift-XRT team, There was an error in GCN Circ. 39633 — Swift is not observing a 22-month old GRB, but is in fact observing combined error locatlisation of GRB 250309B and IceCube 250309A. Apologies for any confusion caused by my errant … [View More]

1 0

[vsnet-grb-info 37649] GRB 230509B: Tiled Swift observations
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39633 SUBJECT: GRB 230509B: Tiled Swift observations DATE: 25/03/09 13:15:21 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a series of observations, tiled on the sky, of the Fermi/GBM GRB 230509B. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00134 Any uncatalogued X-ray sources detected … [View More]

1 0

[vsnet-grb-info 37648] GRB 250308A: SVOM/GRM observation of a bright short burst
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39632 SUBJECT: GRB 250308A: SVOM/GRM observation of a bright short burst DATE: 25/03/09 12:40:35 GMT FROM: Chenwei Wang at IHEP <cwwang(a)ihep.ac.cn> SVOM/GRM team: Chen-Wei Wang, Zheng-Hang Yu, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP) SVOM/ECLAIRs team: Nicolas Dagoneau (CEA), Maria-Grazia Bernardini (INAF-OAB), Jean-Luc Atteia (IRAP), Frédéric Piron (LUPM) Report on behalf of the SVOM team: SVOM/GRM was triggered in-… [View More]

1 0

[vsnet-grb-info 37647] IceCube-250309A - IceCube observation of a high-energy neutrino candidate track-like event
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39631 SUBJECT: IceCube-250309A - IceCube observation of a high-energy neutrino candidate track-like event DATE: 25/03/09 11:48:28 GMT FROM: A. Zegarelli at Ruhr University Bochum <azegarelli(a)icecube.wisc.edu> The IceCube Collaboration (http://icecube.wisc.edu/) reports: On 2025-03-09 at 07:36:04.75 UT IceCube detected a track-like event with a high probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_GOLD … [View More]alert stream. The average astrophysical neutrino purity for Gold alerts is 50%. This alert has an estimated false alarm rate of 0.1759 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection. After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/140626_1288692.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to: Date: 2025-03-09 Time: 07:36:04.75 UT RA: 211.07 (+0.31 -0.30 deg 90% PSF containment) J2000 Dec: -10.73 (+0.26 -0.30 deg 90% PSF containment) J2000 The inferred neutrino energy of this alert is ~4 PeV, making it the fourth-highest energy known detection by IceCube over the past decade. The alert coincides with the Fermi GRB250309B (Fermi-GBM trigger 763198715 at 07:38:30.66 on 09 March 2025; https://gcn.gsfc.nasa.gov/other/763198715.fermi) with a time delay of 145.91 seconds relative to the GRB trigger time. The angular distance to the most updated reconstruction released by the GBM team, which has a 1σ statistical error of 1.60 deg, is 0.77 degrees. An alternative algorithm results in a shifted direction (https://gcn.nasa.gov/circulars/39629) with an angular distance from the best fit neutrino direction of 3.18 degrees and has a 1σ statistical error of 1.3 degree and a systematic error of 1 degree. We strongly encourage follow-up observations of the neutrino region of interest and the uncertainty region of GRB250309B. No known gamma-ray sources listed in the Fermi 4FGL-DR4 or 3FHL catalogs are located within the 90% uncertainty region of the event. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc(a)icecube.wisc.edu View this GCN Circular online at https://gcn.nasa.gov/circulars/39631. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37646] IceCube Alert 250309.32: Global MASTER-Net observations report
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39630 SUBJECT: IceCube Alert 250309.32: Global MASTER-Net observations report DATE: 25/03/09 09:39:41 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. … [View More]Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the IceCube Alert 250309.32 (trigger No 1288692,14h 03m 12.24s , -10d 26m 24.0s, R=0.51) errorbox 9 sec after notice time and 109 sec after trigger time at 2025-03-09 07:37:54 UT, with upper limit up to 21.3 mag. The observations began at zenith distance = 21 deg. The sun altitude is -35.6 deg. The galactic latitude b = 48 deg., longitude l = 331 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2805613 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 120 | 2025-03-09 07:37:54 | MASTER-OAFA | (14h 12m 24.48s , -09d 45m 33.8s) | C | 20 | 18.1 | 135 | 2025-03-09 07:37:54 | MASTER-OAFA | (14h 12m 24.47s , -09d 45m 33.7s) | C | 50 | 18.7 | Coadd 120 | 2025-03-09 07:37:54 | MASTER-OAFA | (14h 03m 05.50s , -10d 07m 35.4s) | C | 20 | 20.1 | 155 | 2025-03-09 07:37:54 | MASTER-OAFA | (14h 03m 05.50s , -10d 07m 35.4s) | C | 90 | 21.1 | Coadd 490 | 2025-03-09 07:37:54 | MASTER-OAFA | (14h 03m 05.50s , -10d 07m 35.4s) | C | 760 | 21.0 | Coadd 154 | 2025-03-09 07:38:34 | MASTER-OAFA | (14h 12m 24.51s , -09d 45m 31.7s) | C | 10 | 17.5 | 165 | 2025-03-09 07:38:34 | MASTER-OAFA | (14h 03m 05.53s , -10d 07m 33.6s) | C | 30 | 20.4 | 196 | 2025-03-09 07:39:10 | MASTER-OAFA | (14h 12m 24.55s , -09d 45m 29.5s) | C | 20 | 18.1 | 206 | 2025-03-09 07:39:10 | MASTER-OAFA | (14h 03m 05.54s , -10d 07m 32.1s) | C | 40 | 20.6 | 247 | 2025-03-09 07:39:56 | MASTER-OAFA | (14h 12m 24.59s , -09d 45m 27.0s) | C | 30 | 18.6 | 292 | 2025-03-09 07:39:56 | MASTER-OAFA | (14h 12m 24.59s , -09d 45m 27.0s) | C | 120 | 19.6 | Coadd 257 | 2025-03-09 07:39:57 | MASTER-OAFA | (14h 03m 05.56s , -10d 07m 30.4s) | C | 50 | 20.7 | 322 | 2025-03-09 07:39:57 | MASTER-OAFA | (14h 03m 05.56s , -10d 07m 30.5s) | C | 180 | 21.0 | Coadd 308 | 2025-03-09 07:40:52 | MASTER-OAFA | (14h 12m 24.62s , -09d 45m 24.4s) | C | 40 | 18.7 | 318 | 2025-03-09 07:40:53 | MASTER-OAFA | (14h 03m 05.58s , -10d 07m 28.6s) | C | 60 | 20.8 | 379 | 2025-03-09 07:41:58 | MASTER-OAFA | (14h 12m 24.64s , -09d 45m 21.7s) | C | 50 | 18.9 | 389 | 2025-03-09 07:41:59 | MASTER-OAFA | (14h 03m 05.59s , -10d 07m 26.6s) | C | 70 | 20.8 | 466 | 2025-03-09 07:43:15 | MASTER-OAFA | (14h 12m 24.68s , -09d 45m 18.7s) | C | 70 | 19.0 | 566 | 2025-03-09 07:43:15 | MASTER-OAFA | (14h 12m 24.69s , -09d 45m 18.7s) | C | 270 | 20.2 | Coadd 476 | 2025-03-09 07:43:15 | MASTER-OAFA | (14h 03m 05.61s , -10d 07m 24.2s) | C | 90 | 20.9 | 596 | 2025-03-09 07:43:15 | MASTER-OAFA | (14h 03m 05.61s , -10d 07m 24.2s) | C | 330 | 21.3 | Coadd 572 | 2025-03-09 07:44:51 | MASTER-OAFA | (14h 12m 24.72s , -09d 45m 15.1s) | C | 90 | 19.3 | 582 | 2025-03-09 07:44:51 | MASTER-OAFA | (14h 03m 05.63s , -10d 07m 21.3s) | C | 110 | 20.9 | 698 | 2025-03-09 07:46:47 | MASTER-OAFA | (14h 12m 24.74s , -09d 45m 11.3s) | C | 110 | 19.5 | 708 | 2025-03-09 07:46:47 | MASTER-OAFA | (14h 03m 05.66s , -10d 07m 17.9s) | C | 130 | 20.8 | 849 | 2025-03-09 07:49:03 | MASTER-OAFA | (14h 12m 24.76s , -09d 45m 07.0s) | C | 140 | 19.5 | 1009 | 2025-03-09 07:49:03 | MASTER-OAFA | (14h 12m 24.76s , -09d 45m 07.0s) | C | 460 | 20.3 | Coadd 859 | 2025-03-09 07:49:03 | MASTER-OAFA | (14h 03m 05.69s , -10d 07m 14.1s) | C | 160 | 20.7 | 1039 | 2025-03-09 07:49:03 | MASTER-OAFA | (14h 03m 05.69s , -10d 07m 14.1s) | C | 520 | 20.5 | Coadd 1025 | 2025-03-09 07:51:50 | MASTER-OAFA | (14h 12m 24.78s , -09d 45m 02.4s) | C | 160 | 19.7 | 1036 | 2025-03-09 07:51:50 | MASTER-OAFA | (14h 03m 05.70s , -10d 07m 09.7s) | C | 180 | 20.6 | 1212 | 2025-03-09 07:54:56 | MASTER-OAFA | (14h 12m 24.76s , -09d 44m 57.9s) | C | 160 | 19.6 | 1222 | 2025-03-09 07:54:56 | MASTER-OAFA | (14h 03m 05.69s , -10d 07m 05.4s) | C | 180 | 20.6 | 1398 | 2025-03-09 07:58:02 | MASTER-OAFA | (14h 12m 24.74s , -09d 44m 53.3s) | C | 160 | 19.8 | 1558 | 2025-03-09 07:58:02 | MASTER-OAFA | (14h 12m 24.74s , -09d 44m 53.3s) | C | 480 | 20.3 | Coadd 1408 | 2025-03-09 07:58:03 | MASTER-OAFA | (14h 03m 05.69s , -10d 07m 00.9s) | C | 180 | 20.6 | 1588 | 2025-03-09 07:58:03 | MASTER-OAFA | (14h 03m 05.69s , -10d 07m 00.9s) | C | 540 | 20.5 | Coadd 1584 | 2025-03-09 08:01:08 | MASTER-OAFA | (14h 12m 24.74s , -09d 44m 49.1s) | C | 160 | 19.7 | 1594 | 2025-03-09 08:01:08 | MASTER-OAFA | (14h 03m 05.70s , -10d 06m 56.7s) | C | 180 | 20.6 | 1770 | 2025-03-09 08:04:15 | MASTER-OAFA | (14h 12m 24.73s , -09d 44m 44.9s) | C | 160 | 19.6 | 1781 | 2025-03-09 08:04:15 | MASTER-OAFA | (14h 03m 05.73s , -10d 06m 52.4s) | C | 180 | 20.7 | 1957 | 2025-03-09 08:07:21 | MASTER-OAFA | (14h 12m 24.72s , -09d 44m 40.7s) | C | 160 | 19.7 | 2117 | 2025-03-09 08:07:21 | MASTER-OAFA | (14h 12m 24.72s , -09d 44m 40.7s) | C | 480 | 20.3 | Coadd 1967 | 2025-03-09 08:07:22 | MASTER-OAFA | (14h 03m 05.75s , -10d 06m 48.3s) | C | 180 | 20.5 | 2147 | 2025-03-09 08:07:22 | MASTER-OAFA | (14h 03m 05.76s , -10d 06m 48.4s) | C | 540 | 20.5 | Coadd 2143 | 2025-03-09 08:10:27 | MASTER-OAFA | (14h 12m 24.71s , -09d 44m 36.8s) | C | 160 | 19.6 | 2153 | 2025-03-09 08:10:28 | MASTER-OAFA | (14h 03m 05.79s , -10d 06m 44.3s) | C | 180 | 20.6 | 2329 | 2025-03-09 08:13:34 | MASTER-OAFA | (14h 12m 24.71s , -09d 44m 33.2s) | C | 160 | 19.7 | 2340 | 2025-03-09 08:13:34 | MASTER-OAFA | (14h 03m 05.84s , -10d 06m 40.6s) | C | 180 | 20.8 | 2515 | 2025-03-09 08:16:39 | MASTER-OAFA | (14h 12m 24.68s , -09d 44m 29.5s) | C | 160 | 19.7 | 2675 | 2025-03-09 08:16:39 | MASTER-OAFA | (14h 12m 24.68s , -09d 44m 29.5s) | C | 480 | 20.3 | Coadd 2526 | 2025-03-09 08:16:40 | MASTER-OAFA | (14h 03m 05.85s , -10d 06m 36.6s) | C | 180 | 20.6 | 2706 | 2025-03-09 08:16:40 | MASTER-OAFA | (14h 03m 05.85s , -10d 06m 36.6s) | C | 540 | 20.7 | Coadd 2702 | 2025-03-09 08:19:46 | MASTER-OAFA | (14h 12m 24.68s , -09d 44m 25.6s) | C | 160 | 19.6 | 2712 | 2025-03-09 08:19:46 | MASTER-OAFA | (14h 03m 05.90s , -10d 06m 32.8s) | C | 180 | 20.7 | 2888 | 2025-03-09 08:22:52 | MASTER-OAFA | (14h 12m 24.64s , -09d 44m 22.0s) | C | 160 | 19.6 | 2898 | 2025-03-09 08:22:52 | MASTER-OAFA | (14h 03m 05.91s , -10d 06m 28.7s) | C | 180 | 20.7 | 3074 | 2025-03-09 08:25:58 | MASTER-OAFA | (14h 12m 24.59s , -09d 44m 18.7s) | C | 160 | 19.6 | 3234 | 2025-03-09 08:25:58 | MASTER-OAFA | (14h 12m 24.59s , -09d 44m 18.6s) | C | 480 | 20.5 | Coadd 3084 | 2025-03-09 08:25:59 | MASTER-OAFA | (14h 03m 05.93s , -10d 06m 25.4s) | C | 180 | 20.8 | 3264 | 2025-03-09 08:25:59 | MASTER-OAFA | (14h 03m 05.93s , -10d 06m 25.3s) | C | 540 | 20.6 | Coadd 3260 | 2025-03-09 08:29:05 | MASTER-OAFA | (14h 12m 24.55s , -09d 44m 15.1s) | C | 160 | 19.7 | 3271 | 2025-03-09 08:29:05 | MASTER-OAFA | (14h 03m 05.93s , -10d 06m 21.3s) | C | 180 | 20.6 | 3447 | 2025-03-09 08:32:11 | MASTER-OAFA | (14h 12m 24.52s , -09d 44m 11.8s) | C | 160 | 19.6 | 3457 | 2025-03-09 08:32:11 | MASTER-OAFA | (14h 03m 05.91s , -10d 06m 17.9s) | C | 180 | 20.6 | 3633 | 2025-03-09 08:35:18 | MASTER-OAFA | (14h 12m 24.48s , -09d 44m 08.4s) | C | 160 | 19.7 | 3793 | 2025-03-09 08:35:18 | MASTER-OAFA | (14h 12m 24.48s , -09d 44m 08.5s) | C | 480 | 20.4 | Coadd 3644 | 2025-03-09 08:35:18 | MASTER-OAFA | (14h 03m 05.92s , -10d 06m 14.4s) | C | 180 | 20.6 | 3824 | 2025-03-09 08:35:18 | MASTER-OAFA | (14h 03m 05.92s , -10d 06m 14.3s) | C | 540 | 20.5 | Coadd 3819 | 2025-03-09 08:38:24 | MASTER-OAFA | (14h 12m 24.44s , -09d 44m 05.3s) | C | 160 | 19.7 | 3830 | 2025-03-09 08:38:24 | MASTER-OAFA | (14h 03m 05.93s , -10d 06m 11.1s) | C | 180 | 20.6 | 4006 | 2025-03-09 08:41:30 | MASTER-OAFA | (14h 12m 24.42s , -09d 44m 02.4s) | C | 160 | 19.7 | 4016 | 2025-03-09 08:41:30 | MASTER-OAFA | (14h 03m 05.95s , -10d 06m 07.8s) | C | 180 | 20.6 | 4192 | 2025-03-09 08:44:36 | MASTER-OAFA | (14h 12m 24.38s , -09d 43m 59.5s) | C | 160 | 19.7 | 4352 | 2025-03-09 08:44:36 | MASTER-OAFA | (14h 12m 24.38s , -09d 43m 59.4s) | C | 480 | 20.4 | Coadd 4202 | 2025-03-09 08:44:36 | MASTER-OAFA | (14h 03m 05.96s , -10d 06m 04.4s) | C | 180 | 20.6 | 4382 | 2025-03-09 08:44:36 | MASTER-OAFA | (14h 03m 05.96s , -10d 06m 04.4s) | C | 540 | 20.6 | Coadd 4378 | 2025-03-09 08:47:42 | MASTER-OAFA | (14h 12m 24.33s , -09d 43m 56.5s) | C | 160 | 19.6 | 4388 | 2025-03-09 08:47:42 | MASTER-OAFA | (14h 03m 05.98s , -10d 06m 01.1s) | C | 180 | 20.6 | 4564 | 2025-03-09 08:50:48 | MASTER-OAFA | (14h 12m 24.26s , -09d 43m 53.8s) | C | 160 | 19.7 | 4574 | 2025-03-09 08:50:48 | MASTER-OAFA | (14h 03m 06.00s , -10d 05m 58.2s) | C | 180 | 20.6 | 4750 | 2025-03-09 08:53:54 | MASTER-OAFA | (14h 12m 24.22s , -09d 43m 51.1s) | C | 160 | 19.8 | 4910 | 2025-03-09 08:53:54 | MASTER-OAFA | (14h 12m 24.22s , -09d 43m 51.1s) | C | 480 | 20.4 | Coadd 4760 | 2025-03-09 08:53:54 | MASTER-OAFA | (14h 03m 06.02s , -10d 05m 55.4s) | C | 180 | 20.7 | 4940 | 2025-03-09 08:53:54 | MASTER-OAFA | (14h 03m 06.02s , -10d 05m 55.4s) | C | 540 | 20.7 | Coadd 4936 | 2025-03-09 08:57:00 | MASTER-OAFA | (14h 12m 24.13s , -09d 43m 48.7s) | C | 160 | 19.6 | 4946 | 2025-03-09 08:57:00 | MASTER-OAFA | (14h 03m 06.02s , -10d 05m 52.7s) | C | 180 | 20.6 | 5122 | 2025-03-09 09:00:06 | MASTER-OAFA | (14h 12m 24.08s , -09d 43m 46.1s) | C | 160 | 19.7 | 5132 | 2025-03-09 09:00:06 | MASTER-OAFA | (14h 03m 06.03s , -10d 05m 50.1s) | C | 180 | 20.6 | 5307 | 2025-03-09 09:03:12 | MASTER-OAFA | (14h 12m 24.05s , -09d 43m 43.6s) | C | 160 | 19.7 | 5467 | 2025-03-09 09:03:12 | MASTER-OAFA | (14h 12m 24.05s , -09d 43m 43.6s) | C | 480 | 20.3 | Coadd 5318 | 2025-03-09 09:03:12 | MASTER-OAFA | (14h 03m 06.04s , -10d 05m 47.4s) | C | 180 | 20.7 | 5498 | 2025-03-09 09:03:12 | MASTER-OAFA | (14h 03m 06.04s , -10d 05m 47.4s) | C | 540 | 20.6 | Coadd 5493 | 2025-03-09 09:06:18 | MASTER-OAFA | (14h 12m 24.00s , -09d 43m 41.3s) | C | 160 | 19.6 | 5504 | 2025-03-09 09:06:18 | MASTER-OAFA | (14h 03m 06.04s , -10d 05m 44.8s) | C | 180 | 20.6 | 5680 | 2025-03-09 09:09:24 | MASTER-OAFA | (14h 12m 23.93s , -09d 43m 39.2s) | C | 160 | 19.6 | 5690 | 2025-03-09 09:09:24 | MASTER-OAFA | (14h 03m 06.09s , -10d 05m 42.5s) | C | 180 | 20.6 | 5866 | 2025-03-09 09:12:30 | MASTER-OAFA | (14h 12m 23.88s , -09d 43m 37.0s) | C | 160 | 19.6 | 6026 | 2025-03-09 09:12:30 | MASTER-OAFA | (14h 12m 23.88s , -09d 43m 37.0s) | C | 480 | 20.3 | Coadd 5876 | 2025-03-09 09:12:31 | MASTER-OAFA | (14h 03m 06.10s , -10d 05m 40.2s) | C | 180 | 20.6 | 6056 | 2025-03-09 09:12:31 | MASTER-OAFA | (14h 03m 06.10s , -10d 05m 40.2s) | C | 540 | 20.4 | Coadd 6052 | 2025-03-09 09:15:36 | MASTER-OAFA | (14h 12m 23.83s , -09d 43m 35.0s) | C | 160 | 19.6 | 6062 | 2025-03-09 09:15:36 | MASTER-OAFA | (14h 03m 06.11s , -10d 05m 38.0s) | C | 180 | 20.6 | 6238 | 2025-03-09 09:18:42 | MASTER-OAFA | (14h 12m 23.77s , -09d 43m 33.0s) | C | 160 | 19.6 | 6248 | 2025-03-09 09:18:42 | MASTER-OAFA | (14h 03m 06.11s , -10d 05m 35.8s) | C | 180 | 20.7 | 6424 | 2025-03-09 09:21:48 | MASTER-OAFA | (14h 12m 23.72s , -09d 43m 31.3s) | C | 160 | 19.5 | 6584 | 2025-03-09 09:21:48 | MASTER-OAFA | (14h 12m 23.72s , -09d 43m 31.3s) | C | 480 | 20.3 | Coadd 6434 | 2025-03-09 09:21:49 | MASTER-OAFA | (14h 03m 06.12s , -10d 05m 33.9s) | C | 180 | 20.6 | 6610 | 2025-03-09 09:24:54 | MASTER-OAFA | (14h 12m 23.65s , -09d 43m 29.5s) | C | 160 | 19.5 | 6620 | 2025-03-09 09:24:55 | MASTER-OAFA | (14h 03m 06.14s , -10d 05m 31.9s) | C | 180 | 20.6 | 6796 | 2025-03-09 09:28:00 | MASTER-OAFA | (14h 12m 23.59s , -09d 43m 27.9s) | C | 160 | 19.4 | 6806 | 2025-03-09 09:28:01 | MASTER-OAFA | (14h 03m 06.16s , -10d 05m 30.1s) | C | 180 | 20.5 | 6983 | 2025-03-09 09:31:07 | MASTER-OAFA | (14h 12m 23.52s , -09d 43m 26.7s) | C | 160 | 19.2 | 6993 | 2025-03-09 09:31:07 | MASTER-OAFA | (14h 03m 06.19s , -10d 05m 28.9s) | C | 180 | 20.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/39630. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 37645] GRB 250309B: BALROG localization (Fermi Trigger 763198715 / GRB 250309318)
by GCN Circulars 09 Mar '25

09 Mar '25

TITLE: GCN CIRCULAR NUMBER: 39629 SUBJECT: GRB 250309B: BALROG localization (Fermi Trigger 763198715 / GRB 250309318) DATE: 25/03/09 08:04:59 GMT FROM: Jochen Greiner at MPE <jcgrog(a)mpe.mpg.de> T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 763198715 at 07:38:30 on 09 March 2025 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS … [View More]

1 0