GRB 260703A
GCN Circular 45067
Subject
Fermi GRB 260703A: Global MASTER-Net observations report
Date
2026-07-03T04:32:19Z (7 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),
M. Segura, 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-OAGH robotic telescope [1] located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB 260703A ( Fermi GBM team, GCN 45066) errorbox 4679 sec after notice time and 4712 sec after trigger time at 2026-07-03 03:33:19 UT, with upper limit up to 18.7 mag. Observations started at twilight. The observations began at zenith distance = 72 deg. The sun altitude is -12.7 deg.
The galactic latitude b = 2 deg., longitude l = 113 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3412712
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
4742 | 2026-07-03 03:33:19 | MASTER-OAGH | (22h 55m 39.05s , +66d 56m 42.8s) | C | 60 | 16.9 |
4742 | 2026-07-03 03:33:19 | MASTER-OAGH | (22h 40m 24.15s , +67d 36m 09.7s) | C | 60 | 16.4 |
4815 | 2026-07-03 03:34:32 | MASTER-OAGH | (22h 55m 44.27s , +66d 55m 36.7s) | C | 60 | 17.0 |
4815 | 2026-07-03 03:34:32 | MASTER-OAGH | (22h 40m 30.26s , +67d 35m 03.6s) | C | 60 | 16.6 |
4891 | 2026-07-03 03:35:48 | MASTER-OAGH | (23h 55m 18.75s , +68d 50m 07.3s) | C | 60 | 17.2 |
4891 | 2026-07-03 03:35:48 | MASTER-OAGH | (23h 38m 45.84s , +69d 30m 09.3s) | C | 60 | 16.7 |
4972 | 2026-07-03 03:37:09 | MASTER-OAGH | (22h 18m 30.52s , +65d 39m 41.5s) | C | 60 | 17.0 |
4972 | 2026-07-03 03:37:09 | MASTER-OAGH | (22h 32m 37.85s , +65d 00m 33.9s) | C | 60 | 17.3 |
5048 | 2026-07-03 03:38:25 | MASTER-OAGH | (22h 18m 28.10s , +65d 40m 16.0s) | C | 60 | 17.0 |
5048 | 2026-07-03 03:38:25 | MASTER-OAGH | (22h 32m 35.76s , +65d 01m 08.8s) | C | 60 | 17.4 |
7477 | 2026-07-03 04:18:54 | MASTER-OAGH | (22h 27m 21.10s , +66d 52m 48.7s) | C | 60 | 18.5 |
7477 | 2026-07-03 04:18:54 | MASTER-OAGH | (22h 12m 20.69s , +67d 31m 22.6s) | C | 60 | 17.8 |
7552 | 2026-07-03 04:20:09 | MASTER-OAGH | (23h 26m 37.26s , +70d 41m 38.4s) | C | 60 | 18.6 |
7552 | 2026-07-03 04:20:09 | MASTER-OAGH | (23h 08m 47.46s , +71d 21m 01.8s) | C | 60 | 18.0 |
7635 | 2026-07-03 04:21:31 | MASTER-OAGH | (00h 00m 28.54s , +70d 44m 10.6s) | C | 60 | 18.5 |
7635 | 2026-07-03 04:21:31 | MASTER-OAGH | (23h 42m 37.15s , +71d 23m 51.5s) | C | 60 | 17.8 |
7710 | 2026-07-03 04:22:47 | MASTER-OAGH | (22h 52m 44.70s , +70d 41m 44.6s) | C | 60 | 18.7 |
7784 | 2026-07-03 04:24:01 | MASTER-OAGH | (22h 52m 44.99s , +70d 41m 43.6s) | C | 60 | 18.6 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
[1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp.
http : // www.pereplet.ru/lipunov/625.html
GCN Circular 45066
Subject
GRB 260703A: Fermi GBM Final Localization
Date
2026-07-03T03:47:10Z (7 days ago)
From
Matt Godwin <msg0028@uah.edu>
Via
Web form
The Fermi GBM team reports the detection of a likely SHORT GRB
"At 02:14:47.19 UT on 03 July 2026, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 260703A (trigger 804737692/260703094).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 350.51, Dec = 63.36 (J2000 degrees, equivalent to J2000 23h 22m, +63d 21'),
with a statistical uncertainty of 6.72 degrees.
The angle from the Fermi LAT boresight is 29 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260703094/quicklook/glg_skymap_all_bn260703094.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260703094/quicklook/glg_healpix_all_bn260703094.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260703094/quicklook/glg_lc_medres34_bn260703094.gif"