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

[vsnet-grb-info 38781] EP-WXT trigger 01709178875: confirmation of a stellar flare by BOOTES-6
by GCN Circulars 16 Jun '25

16 Jun '25

TITLE: GCN CIRCULAR NUMBER: 40741 SUBJECT: EP-WXT trigger 01709178875: confirmation of a stellar flare by BOOTES-6 DATE: 25/06/16 06:51:28 GMT FROM: I. Perez-Garcia at Institute of Astrophysics of Andalusia <ipg(a)iaa.es> I. Perez-Garcia, S.-Y. Wu, A. J. Castro-Tirado, E. J. Fernandez-Garcia, M.D. Caballero-Garcia, S. Guziy, G. Garcia-Segura, R. Sanchez-Ramirez (IAA-CSIC), Y.-D. Hu (INAF-OAB), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), , M. Gritsevich (Univ. of Helsinki), D.-R. Xiong (Yunnan Observatories of CAS), B.-B. Zhang (Nanjing Univ.), P. J. Meintjes and H. J. van Heerden (UFS, South Africa), A. Martin-Carrillo and L. Hanlon (UCD, Ireland), on behalf of a larger collaboration, report: Following the detection of trigger 01709178875 by EP-WXT (Zhao et al. GCN 40740), the 0.6m robotic telescope BOOTES-6/DPRT at Boyden Observatory in Maselspoort (South Africa) responded to the alert on June 15, 16:35 UT (i.e. 23 min after notification and 29 min after the detection). Within the reported EP error circle we find the star SZ 67 decreasing 1.6 mag in brightness (g filter) and 1 mag (r filter) during a 240 min time interval, confirming the EP X-ray trigger due to a stellar flare. We thank the staff at Boyden Observatory for their excellent support. View this GCN Circular online at https://gcn.nasa.gov/circulars/40741. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38780] The EP-WXT trigger 01709178875 is likely a flaring star
by GCN Circulars 16 Jun '25

16 Jun '25

TITLE: GCN CIRCULAR NUMBER: 40740 SUBJECT: The EP-WXT trigger 01709178875 is likely a flaring star DATE: 25/06/16 04:17:09 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> Y.Q.Zhao(USTC,PRIC),Y.P.Zhou(NJU),X.L.Chen(YNU),M.J.Liu,C.C.Jin(NAO, CAS) on behalf of the Einstein Probe (EP) team: The EP-WXT trigger 01709178875 at the time of 2025-06-15T16:06:24, is likely a stellar flare associated with T Tauri Star SZ 67. The estimated flux of the flare is around 1.18e-10 erg/s/cm^2 in 0.5-4.0 keV, corresponding to an X-ray luminosity of around 1.51e32 erg/s. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). View this GCN Circular online at https://gcn.nasa.gov/circulars/40740. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38779] GRB 250615A: Enhanced Swift-XRT position
by GCN Circulars 16 Jun '25

16 Jun '25

TITLE: GCN CIRCULAR NUMBER: 40739 SUBJECT: GRB 250615A: Enhanced Swift-XRT position DATE: 25/06/16 02:49:06 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 1622 s of XRT Photon Counting mode data and 1 UVOT images for GRB 250615A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 290.38565, +4.68515 which is equivalent to: RA (J2000): 19h 21m 32.56s Dec (J2000): +04d 41' 06.5" with an uncertainty of 2.3 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/40739. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38778] Fermi Gamma-ray Burst Monitor trigger 771718064/250615922 is not a GRB
by GCN Circulars 16 Jun '25

16 Jun '25

TITLE: GCN CIRCULAR NUMBER: 40738 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 771718064/250615922 is not a GRB DATE: 25/06/16 01:58:38 GMT FROM: sumanbala2210(a)gmail.com S. Bala (USRA) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 771718064/250615922 at 22:07:39.34 UT on 15 June 2025, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to local particles." View this GCN Circular online at https://gcn.nasa.gov/circulars/40738. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38777] GRB 250615A: Prompt enhanced Swift-XRT position
by GCN Circulars 15 Jun '25

15 Jun '25

TITLE: GCN CIRCULAR NUMBER: 40737 SUBJECT: GRB 250615A: Prompt enhanced Swift-XRT position DATE: 25/06/15 23:00:07 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-XRT team: Using 1.0 ks of promptly downlinked XRT event data for GRB 250615A, we find an enhanced XRT position of the afterglow: RA, Dec: 290.38555, 4.68527 which is equivalent to: RA (J2000) = 19 21 32.53 Dec (J2000) = +04 41 07.0 with an uncertainty of 2.0 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/1324646. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/40737. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38776] GRB 250615A: Swift detection of a burst
by GCN Circulars 15 Jun '25

15 Jun '25

TITLE: GCN CIRCULAR NUMBER: 40736 SUBJECT: GRB 250615A: Swift detection of a burst DATE: 25/06/15 22:44:24 GMT FROM: Simone Dichiara at Pennsylvania State University <sbd5667(a)psu.edu> S. Dichiara (PSU), J. J. DeLaunay (PSU), R. Gupta (NASA GSFC) and T. Sakamoto (AGU) report on behalf of the Neil Gehrels Swift Observatory Team: At 22:25:19.59 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 250615A (trigger=1324646). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 290.344, +4.672 which is RA(J2000) = 19h 21m 23s Dec(J2000) = +04d 40â 21" 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 55 sec. The peak count rate was ~5000 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 22:26:46.4 UT, 86.9 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 290.38466, 4.68467 which is equivalent to: RA(J2000) = 19h 21m 32.32s Dec(J2000) = +04d 41' 04.8" with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 152 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 does not constrain the column density. The initial flux in the 2.5 s image was 9.89e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 250 seconds with the U filter starting 152 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. Results from the 2.7'x2.7' sub-image are not available at this time. 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 18.0 mag. No correction has been made for the large, but uncertain, extinction expected. Burst Advocate for this burst is S. Dichiara (sbd5667 AT psu.edu). 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/40736. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38775] Swift GRB250615.93: Global MASTER-Net observations report
by GCN Circulars 15 Jun '25

15 Jun '25

TITLE: GCN CIRCULAR NUMBER: 40735 SUBJECT: Swift GRB250615.93: Global MASTER-Net observations report DATE: 25/06/15 22:32:26 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.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) was pointed to the Swift GRB250615.93 (trigger No 1324646,19h 21m 22.56s , +04d 40m 19.2s, R=0.05) errorbox 25 sec after notice time and 42 sec after trigger time at 2025-06-15 22:26:02 UT, with upper limit up to 17.1 mag. The observations began at zenith distance = 46 deg. The sun altitude is -80.9 deg. The galactic latitude b = -5 deg., longitude l = 41 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2903527 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 48 | MASTER-SAAO | C | 10 | 16.9 | 48 | MASTER-SAAO | C | 10 | 17.1 | 77 | MASTER-SAAO | C | 10 | 17.0 | 77 | MASTER-SAAO | C | 10 | 17.1 | 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/40735. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38774] Fermi trigger No 771718064: Global MASTER-Net observations report
by GCN Circulars 15 Jun '25

15 Jun '25

TITLE: GCN CIRCULAR NUMBER: 40734 SUBJECT: Fermi trigger No 771718064: Global MASTER-Net observations report DATE: 25/06/15 22:15:32 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.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 GRB250615.92 (trigger No 771718064,08h 56m 28.80s , -44d 43m 48.0s, R=9.43) errorbox 119 sec after notice time and 154 sec after trigger time at 2025-06-15 22:10:13 UT, with upper limit up to 17.3 mag. The observations began at zenith distance = 83 deg. The sun altitude is -79.2 deg. The galactic latitude b = 1 deg., longitude l = 266 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2903453 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 170 | 2025-06-15 22:10:13 | MASTER-SAAO | (09h 14m 46.22s , -47d 11m 07.1s) | C | 30 | 17.0 | 170 | 2025-06-15 22:10:13 | MASTER-SAAO | (09h 12m 12.28s , -46d 55m 37.8s) | C | 30 | 15.0 | 224 | 2025-06-15 22:11:03 | MASTER-SAAO | (09h 14m 46.07s , -47d 11m 01.9s) | C | 40 | 17.3 | 224 | 2025-06-15 22:11:03 | MASTER-SAAO | (09h 12m 12.19s , -46d 55m 31.5s) | C | 40 | 15.1 | 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/40734. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38773] Fermi Gamma-ray Burst Monitor trigger 771704505/250615765 is not a GRB
by GCN Circulars 15 Jun '25

15 Jun '25

TITLE: GCN CIRCULAR NUMBER: 40733 SUBJECT: Fermi Gamma-ray Burst Monitor trigger 771704505/250615765 is not a GRB DATE: 25/06/15 19:29:24 GMT FROM: rhamburg(a)usra.edu R. Hamburg (USRA) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "The Fermi Gamma-ray Burst Monitor (GBM) trigger 771704505/250615765 at 18:21:40.49 UT on 15 June 2025, tentatively classified as a GRB, is in fact not due to a GRB. This trigger is likely due to solar flare." View this GCN Circular online at https://gcn.nasa.gov/circulars/40733. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 38772] GRID detection of GRB 250612C
by GCN Circulars 15 Jun '25

15 Jun '25

TITLE: GCN CIRCULAR NUMBER: 40732 SUBJECT: GRID detection of GRB 250612C DATE: 25/06/15 16:40:18 GMT FROM: GRID Student Team at Tsinghua University <grid(a)tsinghua.edu.cn> Zirui Yang, Longhao Li and Chenyu Wang report on behalf of the GRID Collaboration: GRID-11B reports the detection of the GRB 250612C, which was also detected by Fermi/GBM (GCN Circular 40704) and SVOM/GRM (GCN Circular 40708). The event was triggered with GRID on 2024-06-12 at 14:53:16 UTC. The measured burst duration (T90) is approximately 2.6 ± 0.9 seconds. The GRID light curve of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB250612C/GRID_GRB…. GRID is a student-led project to monitor the transient gamma-ray sky with multiple detectors onboard different nanosatellites in the era of multi-messenger astronomy. For more information about GRID, please refer to the following references: https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4. View this GCN Circular online at https://gcn.nasa.gov/circulars/40732. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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