May 2025 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 38380] GRB 250504A: SVOM/VT upper limit
by GCN Circulars 05 May '25

05 May '25

TITLE: GCN CIRCULAR NUMBER: 40351 SUBJECT: GRB 250504A: SVOM/VT upper limit DATE: 25/05/05 14:53:47 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> L. P. Xin, Y. L. Qiu, H. L. Li, C. Wu, Z. H. Yao, Y. N. Ma, D.H. Zhao, X. H. Han, Y. Xu, J. Wang, P. P. Zhang, W. J. Xie, Y. J. Xiao, H. B. Cai, L. Lan, J. S. Deng, J. Y. Wei (NAOC) report on behalf of the SVOM/VT Instrument Center: SVOM/VT conducted ToO follow-up observations of GRB 250504A detected by Fermi (Fermi/GBM team, GCN 40342;… [View More]

1 0

[vsnet-grb-info 38379] GRB 250504A: REM optical/NIR observations
by GCN Circulars 05 May '25

05 May '25

TITLE: GCN CIRCULAR NUMBER: 40350 SUBJECT: GRB 250504A: REM optical/NIR observations DATE: 25/05/05 10:35:35 GMT FROM: Riccardo Brivio at INAF-OAB <riccardo.brivio(a)inaf.it> R. Brivio, M. Ferro, P. D'Avanzo, S. Covino, D. Fugazza (INAF-OAB) report on behalf of the REM team: We observed the field of GRB 250504A detected by Fermi/GBM (Fermi GBM team, GCN 40342) and Swift/BAT (Moss et al., GCN 40343) with the REM 60 cm robotic telescope located at the ESO observatory of La Silla (… [View More]

1 0

[vsnet-grb-info 38378] GRB 250502A: REM optical/NIR observations
by GCN Circulars 05 May '25

05 May '25

TITLE: GCN CIRCULAR NUMBER: 40349 SUBJECT: GRB 250502A: REM optical/NIR observations DATE: 25/05/05 10:33:25 GMT FROM: Riccardo Brivio at INAF-OAB <riccardo.brivio(a)inaf.it> R. Brivio, M. Ferro, P. D'Avanzo, S. Covino, D. Fugazza (INAF-OAB) report on behalf of the REM team: We observed the field of GRB 250502A detected by SVOM/ECLAIRs (Wang et al., GCN 40313) with the REM 60 cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried … [View More]

1 0

[vsnet-grb-info 38377] GRB 250505A: Fermi GBM Final Real-time Localization
by GCN Circulars 05 May '25

05 May '25

TITLE: GCN CIRCULAR NUMBER: 40348 SUBJECT: GRB 250505A: Fermi GBM Final Real-time Localization DATE: 25/05/05 08:19:09 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 08:08:39 UT on 5 May 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250505A (trigger 768125324.539978 / 250505339). The on-ground calculated location, using the Fermi GBM trigger data, is RA = … [View More]

1 0

[vsnet-grb-info 38376] GRB 2050504A: MeerLICHT optical afterglow detection
by GCN Circulars 05 May '25

05 May '25

TITLE: GCN CIRCULAR NUMBER: 40347 SUBJECT: GRB 2050504A: MeerLICHT optical afterglow detection DATE: 25/05/05 08:04:54 GMT FROM: Simon de Wet at DTU Space <simdewet(a)gmail.com> S. de Wet (DTU Space), P.M. Vreeswijk (Radboud) and P.J. Groot (Radboud/UCT/SAAO) report on behalf of the MeerLICHT consortium: The 0.6 m wide-field MeerLICHT optical telescope located in Sutherland, South Africa, obtained a repeating series of 60 s exposures in the q,u,g,r,i,z bands of GRB 250504A … [View More]

1 0

[vsnet-grb-info 38375] GRB 250504A: Fermi GBM Observation
by GCN Circulars 05 May '25

05 May '25

TITLE: GCN CIRCULAR NUMBER: 40346 SUBJECT: GRB 250504A: Fermi GBM Observation DATE: 25/05/05 08:00:47 GMT FROM: Elisabetta Bissaldi at Politecnico and INFN Bari <elisabetta.bissaldi(a)ba.infn.it> S. Bala (USRA) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 23:25:54.78 UT on 04 May 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250504A (trigger 768093959/250504976), which was also detected by Swift BAT (M. J. Moss … [View More]

1 0

[vsnet-grb-info 38374] GRB 250504A: Enhanced Swift-XRT position
by GCN Circulars 05 May '25

05 May '25

TITLE: GCN CIRCULAR NUMBER: 40345 SUBJECT: GRB 250504A: Enhanced Swift-XRT position DATE: 25/05/05 07:32:59 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 940 s of XRT Photon Counting mode data and 2 UVOT images for GRB 250504A, 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 38373] Fermi GRB 250504A: Global MASTER-Net observations report
by GCN Circulars 05 May '25

05 May '25

TITLE: GCN CIRCULAR NUMBER: 40344 SUBJECT: Fermi GRB 250504A: Global MASTER-Net observations report DATE: 25/05/05 00:01:03 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov(a)xray.sai.msu.ru> V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.… [View More]Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), 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 250504A ( Fermi GBM team, GCN 40342) errorbox 1 sec after notice time and 43 sec after trigger time at 2025-05-04 23:26:38 UT, with upper limit up to 17.3 mag. The observations began at zenith distance = 29 deg. The sun altitude is -70.3 deg. The galactic latitude b = -6 deg., longitude l = 350 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2860892 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 49 | 2025-05-04 23:26:38 | MASTER-SAAO | (17h 56m 41.66s , -40d 35m 44.3s) | C | 10 | 16.7 | 77 | 2025-05-04 23:27:07 | MASTER-SAAO | (17h 56m 41.67s , -40d 35m 44.8s) | C | 10 | 16.7 | 111 | 2025-05-04 23:27:36 | MASTER-SAAO | (17h 56m 41.71s , -40d 35m 45.1s) | C | 20 | 17.0 | 151 | 2025-05-04 23:28:15 | MASTER-SAAO | (17h 56m 41.72s , -40d 35m 45.3s) | C | 20 | 17.0 | 249 | 2025-05-04 23:29:43 | MASTER-SAAO | (17h 56m 41.65s , -40d 35m 44.1s) | C | 40 | 17.2 | 313 | 2025-05-04 23:30:42 | MASTER-SAAO | (17h 56m 41.63s , -40d 35m 43.6s) | C | 50 | 17.2 | 387 | 2025-05-04 23:31:51 | MASTER-SAAO | (17h 56m 41.55s , -40d 35m 43.1s) | C | 60 | 17.3 | 466 | 2025-05-04 23:33:10 | MASTER-SAAO | (17h 56m 41.50s , -40d 35m 42.3s) | C | 60 | 17.3 | 545 | 2025-05-04 23:34:29 | MASTER-SAAO | (17h 56m 41.40s , -40d 35m 41.4s) | C | 60 | 17.3 | 624 | 2025-05-04 23:35:48 | MASTER-SAAO | (17h 56m 41.29s , -40d 35m 40.5s) | C | 60 | 17.3 | 703 | 2025-05-04 23:37:08 | MASTER-SAAO | (17h 56m 41.19s , -40d 35m 39.7s) | C | 60 | 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/40344. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 38372] GRB 250504A: Swift detection of a burst
by GCN Circulars 04 May '25

04 May '25

TITLE: GCN CIRCULAR NUMBER: 40343 SUBJECT: GRB 250504A: Swift detection of a burst DATE: 25/05/04 23:44:16 GMT FROM: David Palmer at LANL <palmer(a)lanl.gov> M. J. Moss (GSFC), C. Gronwall (PSU), R. Gupta (NASA GSFC), J. A. Kennea (PSU), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 23:25:57 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 250504A (trigger=1310284). Swift slewed immediately to the … [View More]burst. The BAT on-board calculated location is RA, Dec 269.612, -40.349 which is RA(J2000) = 17h 58m 27s Dec(J2000) = -40d 20' 57" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 60 sec. The peak count rate was ~4000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 23:27:15.3 UT, 77.9 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 269.61691, -40.36642 which is equivalent to: RA(J2000) = 17h 58m 28.06s Dec(J2000) = -40d 21' 59.1" with an uncertainty of 1.9 arcseconds (radius, 90% containment). This location is 64 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 consistent with the Galactic value of 2.12 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 250 seconds with the U filter starting 137 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. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the sub-image. The 8'x8' region for the list of sources generated on-board covers 0.00% of the XRT error circle. No correction has been made for the expected extinction corresponding to E(B-V) of 0.191. Burst Advocate for this burst is M. J. Moss (mikejmoss3 AT gmail.com). 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/40343. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L… [View Less]

1 0

[vsnet-grb-info 38371] GRB 250504A: Fermi GBM Final Real-time Localization
by GCN Circulars 04 May '25

04 May '25

TITLE: GCN CIRCULAR NUMBER: 40342 SUBJECT: GRB 250504A: Fermi GBM Final Real-time Localization DATE: 25/05/04 23:36:31 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 23:25:54 UT on 4 May 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250504A (trigger 768093959.78286 / 250504976). The on-ground calculated location, using the Fermi GBM trigger data, is RA = … [View More]

1 0

2025

2024

2023

2022

2021

vsnet-grb-info May 2025