GRBweb by P. Coppin

This page lists all entries on GRB250305A in GRBweb

Summary Fermi GBM GCN 39597 GCN 39599 GCN 39602 GCN 39660

Summary table
Variable	Value	Source
GRB_name_Fermi	GRB250305645
T0	15:28:57 UTC	GCN_circulars,Fermi GBM final loc
ra	223.7000°	GCN_circulars,Optical
decl	-3.0000°	GCN_circulars,Optical
T90	1.856 s	Fermi_GBM
T90_error	0.231 s	Fermi_GBM
T90_start	15:28:57.471 UTC	Fermi_GBM
fluence	1.74e-06 erg/cm²	Fermi_GBM
fluence_error	1.02e-08 erg/cm²	Fermi_GBM
T100	2.327 s
GBM_located	False
mjd	60739.645104166666	GCN_circulars,Fermi GBM final loc

Fermi GBM table
GRB_name_Fermi	GRB250305645
trigger_name	bn250305645
ra	223.7100°
decl	-2.9500°
pos_error	3.45e+00°
datum	2025-03-05
t_trigger	15:28:57.919 UTC
T90	1.856 s
T90_error	0.231 s
T90_start	15:28:57.471 UTC
fluence	1.74e-06 erg/cm²
fluence_error	1.02e-08 erg/cm²
flux_1024	1.02e+01 erg/cm²/s
flux_1024_error	2.88e-01 erg/cm²/s
flux_1024_time	0.00e+00 erg/cm²/s
flux_64	1.58e+01 erg/cm²/s
flux_64_error	1.19e+00 erg/cm²/s

GCN 39597 table
GRB_name	GRB250305A
GCN_number	39597
Detection_method	Fermi GBM final loc
t_trigger	15:28:57 UTC
ra	223.7000°
decl	-3.0000°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 39597 SUBJECT: GRB 250305A: Fermi GBM Final Real-time Localization DATE: 25/03/05 15:39:31 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 15:28:57 UT on 5 Mar 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250305A (trigger 762881342.919284 / 250305645). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 223.7, Dec = -3.0 (J2000 degrees, equivalent to J2000 14h 54m, -3d 00'), with a statistical uncertainty of 5.0 degrees. The angle from the Fermi LAT boresight is 60.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250305645/quicklook/glg_skymap_all_bn250305645.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250305645/quicklook/glg_healpix_all_bn250305645.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250305645/quicklook/glg_lc_medres34_bn250305645.gif

GCN 39599 table
GRB_name	GRB250305A
GCN_number	39599
Detection_method	Fermi GBM Other
Circular_text	TITLE: GCN CIRCULAR NUMBER: 39599 SUBJECT: Fermi GRB 250305A: Global MASTER-Net observations report DATE: 25/03/05 21:32:49 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs 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.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 250305A ( Fermi GBM team, GCN 39597) errorbox 20388 sec after notice time and 20424 sec after trigger time at 2025-03-05 21:09:22 UT, with upper limit up to 18.6 mag. The observations began at zenith distance = 78 deg. The sun altitude is -45.2 deg. The galactic latitude b = 47 deg., longitude l = 353 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2801332 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 20455 | 2025-03-05 21:09:22 | MASTER-SAAO | (14h 34m 50.28s , -02d 29m 23.3s) | C | 60 | 18.3 | 20534 | 2025-03-05 21:10:41 | MASTER-SAAO | (14h 42m 45.22s , -02d 30m 38.4s) | C | 60 | 18.4 | 20613 | 2025-03-05 21:12:01 | MASTER-SAAO | (14h 36m 36.01s , -04d 22m 25.4s) | C | 60 | 18.6 | 20772 | 2025-03-05 21:14:39 | MASTER-SAAO | (14h 44m 39.80s , -04d 22m 36.6s) | C | 60 | 18.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.

GCN 39602 table
GRB_name	GRB250305A
GCN_number	39602
Detection_method	Optical
ra	223.7000°
decl	-3.0000°
Circular_text	TITLE: GCN CIRCULAR NUMBER: 39602 SUBJECT: GRB 250305A: SVOM/GRM observation of a burst DATE: 25/03/06 09:51:52 GMT FROM: zhangjinpeng@ihep.ac.cn SVOM/GRM team: Jin-Peng 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 250305A (SVOM burst-id sb25030508) at 2025-03-05T15:28:58.100 (T0), which was also observed by Fermi/GBM (Fermi GBM team, GCN #39597). With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multi-pulses with a T90 of 4.6 +1.5/-0.9 s in the 15-5000 keV band. In addition, the position of this burst, as determined by Fermi/GBM (GCN #39597, RA: 223.7 deg, DEC: -3.0 deg, Error: 5.0 deg), is located at about 63 degrees from the SVOM optical axis, and outside the ECLAIRs field of view. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb250305A.png The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM/GRM point of contact for this burst is: Jin-Peng Zhang (IHEP) (zhangjinpeng@ihep.ac.cn)

GCN 39660 table
GRB_name	GRB250305A
GCN_number	39660
Detection_method	MAXI Det
t_trigger	1:55:22 UTC
ra	224.3180°
decl	-2.6130°
Circular_text	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 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. 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.