GRB 250711A
GCN Circular 41064
Subject
GRB 250711A: Fermi GBM Final Real-time Localization
Date
2025-07-11T14:50:44Z (4 days ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 14:40:12 UT on 11 Jul 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250711A (trigger 773937617.940244 / 250711611).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 261.2, Dec = 44.9 (J2000 degrees, equivalent to J2000 17h 24m, 44d 53'), with a statistical uncertainty of 1.2 degrees.
The angle from the Fermi LAT boresight is 28.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250711611/quicklook/glg_skymap_all_bn250711611.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/bn250711611/quicklook/glg_healpix_all_bn250711611.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250711611/quicklook/glg_lc_medres34_bn250711611.gif
GCN Circular 41065
Subject
GRB 250711A: BALROG localization (Fermi Trigger 773937617 / GRB 250711611)
Date
2025-07-11T15:08:21Z (4 days ago)
From
Jochen Greiner at MPE <jcgrog@mpe.mpg.de>
Via
email
T. Preis (University of Innsbruck) & J. Greiner (MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
773937617 at 14:40:12 on 11 July 2025 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).
The best-fit position is:
RA(2000.0) = 267.8 deg
Decl.(2000.0) = 35.9 deg
The 1 sigma statistical error radius is 2.1 deg.
We estimate an additional systematic error of 1 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB250711611/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB250711611/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB250711611/json
GCN Circular 41068
Subject
Fermi GRB 250711A: Global MASTER-Net observations report
Date
2025-07-11T20:30:49Z (3 days ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
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-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 250711A ( Fermi GBM team, GCN 41064) errorbox 16346 sec after notice time and 16354 sec after trigger time at 2025-07-11 19:12:47 UT, with upper limit up to 14.3 mag. The observations began at zenith distance = 3 deg. The sun altitude is -19.0 deg.
The galactic latitude b = 33 deg., longitude l = 71 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2932393
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
16384 | 2025-07-11 19:12:47 | MASTER-Kislovodsk | (17h 35m 16.38s , +45d 13m 31.4s) | C | 60 | 14.3 |
16560 | 2025-07-11 19:15:42 | MASTER-Kislovodsk | (17h 23m 53.68s , +45d 14m 28.9s) | C | 60 | 14.1 |
16814 | 2025-07-11 19:19:57 | MASTER-Kislovodsk | (17h 27m 35.59s , +47d 07m 43.8s) | C | 60 | 14.1 |
16990 | 2025-07-11 19:22:53 | MASTER-Kislovodsk | (17h 35m 19.19s , +45d 13m 39.0s) | C | 60 | 14.3 |
17157 | 2025-07-11 19:25:39 | MASTER-Kislovodsk | (17h 25m 01.99s , +45d 04m 21.7s) | C | 60 | 14.1 |
17316 | 2025-07-11 19:28:19 | MASTER-Kislovodsk | (17h 12m 47.71s , +43d 09m 45.1s) | C | 60 | 13.8 |
17396 | 2025-07-11 19:29:38 | MASTER-Kislovodsk | (17h 23m 53.71s , +43d 09m 27.0s) | C | 60 | 14.0 |
17475 | 2025-07-11 19:30:58 | MASTER-Kislovodsk | (17h 16m 58.46s , +46d 58m 51.1s) | C | 60 | 14.0 |
17555 | 2025-07-11 19:32:17 | MASTER-Kislovodsk | (17h 28m 41.84s , +46d 57m 30.3s) | C | 60 | 14.3 |
17725 | 2025-07-11 19:35:07 | MASTER-Kislovodsk | (17h 14m 53.39s , +45d 04m 13.4s) | C | 60 | 14.2 |
17804 | 2025-07-11 19:36:27 | MASTER-Kislovodsk | (17h 24m 56.77s , +45d 02m 55.6s) | C | 60 | 13.9 |
17883 | 2025-07-11 19:37:46 | MASTER-Kislovodsk | (17h 33m 42.38s , +43d 11m 07.6s) | C | 60 | 14.1 |
18042 | 2025-07-11 19:40:25 | MASTER-Kislovodsk | (17h 12m 51.25s , +43d 11m 29.3s) | C | 60 | 13.5 |
18122 | 2025-07-11 19:41:44 | MASTER-Kislovodsk | (17h 23m 46.84s , +43d 10m 09.4s) | C | 60 | 14.1 |
18201 | 2025-07-11 19:43:04 | MASTER-Kislovodsk | (17h 16m 53.40s , +46d 58m 56.6s) | C | 60 | 14.1 |
18281 | 2025-07-11 19:44:23 | MASTER-Kislovodsk | (17h 28m 41.67s , +46d 58m 00.4s) | C | 60 | 14.1 |
19103 | 2025-07-11 19:58:05 | MASTER-Kislovodsk | (17h 14m 39.74s , +45d 06m 31.7s) | C | 60 | 14.2 |
19183 | 2025-07-11 19:59:25 | MASTER-Kislovodsk | (17h 24m 52.80s , +45d 05m 05.2s) | C | 60 | 14.2 |
19262 | 2025-07-11 20:00:45 | MASTER-Kislovodsk | (17h 33m 37.59s , +43d 12m 30.2s) | C | 60 | 14.3 |
19421 | 2025-07-11 20:03:23 | MASTER-Kislovodsk | (17h 12m 39.43s , +43d 12m 29.1s) | C | 60 | 14.1 |
19500 | 2025-07-11 20:04:43 | MASTER-Kislovodsk | (17h 23m 43.29s , +43d 11m 35.5s) | C | 60 | 14.1 |
19580 | 2025-07-11 20:06:03 | MASTER-Kislovodsk | (17h 16m 41.83s , +46d 58m 18.5s) | C | 60 | 14.1 |
19660 | 2025-07-11 20:07:22 | MASTER-Kislovodsk | (17h 28m 32.18s , +46d 58m 57.2s) | C | 60 | 14.0 |
19739 | 2025-07-11 20:08:42 | MASTER-Kislovodsk | (17h 36m 11.71s , +45d 06m 17.3s) | C | 60 | 14.1 |
20058 | 2025-07-11 20:14:00 | MASTER-Kislovodsk | (17h 33m 29.49s , +43d 12m 34.0s) | C | 60 | 14.1 |
20217 | 2025-07-11 20:16:39 | MASTER-Kislovodsk | (17h 12m 38.24s , +43d 10m 13.3s) | C | 60 | 13.8 |
20296 | 2025-07-11 20:17:59 | MASTER-Kislovodsk | (17h 23m 42.07s , +43d 10m 47.1s) | C | 60 | 14.2 |
20376 | 2025-07-11 20:19:18 | MASTER-Kislovodsk | (17h 16m 42.38s , +47d 00m 04.9s) | C | 60 | 13.8 |
20455 | 2025-07-11 20:20:38 | MASTER-Kislovodsk | (17h 28m 26.32s , +46d 58m 17.9s) | C | 60 | 14.1 |
20535 | 2025-07-11 20:21:57 | MASTER-Kislovodsk | (17h 36m 11.04s , +45d 06m 15.9s) | C | 60 | 14.1 |
20694 | 2025-07-11 20:24:36 | MASTER-Kislovodsk | (17h 14m 31.90s , +45d 06m 29.8s) | C | 60 | 13.8 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 41072
Subject
GRB 250711A: SVOM/GRM observation
Date
2025-07-12T09:36:26Z (3 days ago)
Edited On
2025-07-12T17:24:05Z (3 days ago)
From
Chenwei Wang at IHEP <cwwang@ihep.ac.cn>
Edited By
Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Chenwei Wang at IHEP <cwwang@ihep.ac.cn>
Via
Web form
SVOM/GRM team: Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP)
SVOM/ECLAIRs team: Olivier Godet, Sébastien Guillot (IRAP)
Report on behalf of the SVOM team:
SVOM/GRM was triggered in-flight by a bright burst GRB 250711A (SVOM trigger reference: sb25071104) at 2025-07-11T14:40:14.00 UTC (T0), which is also detected by Fermi/GBM (Fermi GBM Team, GCN#41064).
With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of double pulses with a T90 of 38.5 +/-4.0 s in the 15-5000 keV band.
The SVOM/GRM light curve can be found here:
https://www.bursthub.cn//admin/static/svgrb250711A.png
In addition, the position of this burst, as determined by Fermi/GBM (RA= 261.2, DEC= 44.9, GCN#41064), is located at about 48 degrees from the SVOM optical axis, which is just outside the ECLAIRs field of view.
With this localization, the time-averaged spectrum from T0-10 to T0+70 s is best fitted by a power law function with an exponential high-energy cutoff. The power law index is -1.20 +0.09/-0.10 and the cutoff energy, parameterized as Epeak, is 146 +23/-17 keV. The event fluence (10-1000 keV) in this time interval is (1.69 +0.12/-0.10)E-05 erg/cm^2.
The localization of GRB 250711A in the 'Amati' relation diagram is shown at:
https://www.bursthub.cn//admin/static/grb250711A_amati.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 point of contact for this burst is: Chen-Wei Wang (IHEP)(cwwang@ihep.ac.cn)
GCN Circular 41076
Subject
GRB 250711A: DDOTI Optical Upper Limit
Date
2025-07-12T15:29:33Z (3 days ago)
From
sahil.atri@students.uniroma2.eu
Via
Web form
Sahil Atri (U Roma), Rosa L. Becerra (U Roma), Alan M. Watson (UNAM), Camila Angulo Valdez (UNAM), Nat Butler (ASU), Simone Dichiara (Penn State University), Tsvetelina Dimitrova (ASU), Alexander Kutyrev (GSFC/UMD), William H. Lee (UNAM), Océlotl López (UNAM), Margarita Pereyra (UNAM) and Eleonora Troja (U Roma) report:
We observed the field of GRB 250711A detected by Fermi/GBM (Fermi GBM Team, GCN Circ. 41064) and SVOM/GRM (SVOM/GRM Team GCN Circ. 41072) with the DDOTI/OAN wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir (http://ddoti.astroscu.unam.mx) on the night of 2025-07-12 UTC.
DDOTI observed the BALROG error region (Pries et al., GCN Circ. 41065) from 04:12 UTC to 11:28 UTC (from T+ 13.5 h to T+ 20.8 h after the trigger) and obtained a total exposure of 1.7 hours, alternating with other scientific programs.
Comparing our observations to the USNO-B1 and Pan-STARRS PS1 DR2 catalogues, we
detect no uncatalogued fading sources within the observed field down to a 10-sigma limiting AB magnitude of:
w > 20.1
This value is not corrected for the Galactic extinction.