GCN Circular 41098
Subject
Fermi GRB 250715A: Global MASTER-Net observations report
Event
Date
2025-07-15T17:31:36Z (5 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-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 250715A ( Fermi GBM team, GCN 41097) errorbox 6778 sec after notice time and 6809 sec after trigger time at 2025-07-15 16:47:48 UT, with upper limit up to 19.0 mag. Observations started at twilight. The observations began at zenith distance = 73 deg. The sun altitude is -11.8 deg.
The galactic latitude b = 72 deg., longitude l = 88 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2936965
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
6840 | 2025-07-15 16:47:48 | MASTER-SAAO | (13h 39m 24.98s , +41d 17m 09.8s) | C | 60 | 17.4 |
6840 | 2025-07-15 16:47:48 | MASTER-SAAO | (13h 41m 45.27s , +41d 01m 47.1s) | C | 60 | 17.4 |
6933 | 2025-07-15 16:49:21 | MASTER-SAAO | (13h 49m 58.86s , +41d 14m 56.3s) | C | 60 | 17.5 |
6933 | 2025-07-15 16:49:21 | MASTER-SAAO | (13h 52m 19.04s , +40d 59m 32.5s) | C | 60 | 17.5 |
7121 | 2025-07-15 16:52:30 | MASTER-SAAO | (13h 36m 16.48s , +39d 23m 35.6s) | C | 60 | 18.2 |
7121 | 2025-07-15 16:52:30 | MASTER-SAAO | (13h 38m 33.02s , +39d 08m 13.3s) | C | 60 | 18.0 |
7665 | 2025-07-15 17:01:34 | MASTER-SAAO | (13h 46m 43.77s , +39d 21m 51.3s) | C | 60 | 18.6 |
7665 | 2025-07-15 17:01:34 | MASTER-SAAO | (13h 49m 00.33s , +39d 06m 23.4s) | C | 60 | 18.6 |
7759 | 2025-07-15 17:03:07 | MASTER-SAAO | (13h 39m 31.43s , +41d 17m 22.0s) | C | 60 | 18.7 |
7759 | 2025-07-15 17:03:07 | MASTER-SAAO | (13h 41m 51.72s , +41d 01m 53.4s) | C | 60 | 18.6 |
7852 | 2025-07-15 17:04:41 | MASTER-SAAO | (13h 50m 06.50s , +41d 15m 29.6s) | C | 60 | 18.7 |
7852 | 2025-07-15 17:04:41 | MASTER-SAAO | (13h 52m 26.74s , +41d 00m 00.9s) | C | 60 | 18.7 |
8040 | 2025-07-15 17:07:48 | MASTER-SAAO | (13h 36m 21.22s , +39d 23m 06.4s) | C | 60 | 19.0 |
8040 | 2025-07-15 17:07:49 | MASTER-SAAO | (13h 38m 37.98s , +39d 07m 39.5s) | C | 60 | 18.9 |
8230 | 2025-07-15 17:10:58 | MASTER-SAAO | (13h 43m 46.68s , +43d 09m 56.5s) | C | 60 | 18.8 |
8230 | 2025-07-15 17:10:58 | MASTER-SAAO | (13h 46m 11.14s , +42d 54m 27.8s) | C | 60 | 18.5 |
8325 | 2025-07-15 17:12:33 | MASTER-SAAO | (13h 54m 46.94s , +43d 09m 33.9s) | C | 60 | 18.9 |
8325 | 2025-07-15 17:12:33 | MASTER-SAAO | (13h 57m 11.37s , +42d 54m 04.2s) | C | 60 | 18.8 |
8418 | 2025-07-15 17:14:06 | MASTER-SAAO | (13h 46m 44.39s , +39d 23m 28.0s) | C | 60 | 19.0 |
8418 | 2025-07-15 17:14:06 | MASTER-SAAO | (13h 49m 01.18s , +39d 07m 60.0s) | C | 60 | 19.0 |
8511 | 2025-07-15 17:15:40 | MASTER-SAAO | (13h 39m 34.83s , +41d 16m 33.4s) | C | 60 | 18.9 |
8511 | 2025-07-15 17:15:40 | MASTER-SAAO | (13h 41m 55.31s , +41d 01m 04.1s) | C | 60 | 18.8 |
8605 | 2025-07-15 17:17:13 | MASTER-SAAO | (13h 50m 14.55s , +41d 17m 42.6s) | C | 60 | 18.9 |
8605 | 2025-07-15 17:17:13 | MASTER-SAAO | (13h 52m 35.07s , +41d 02m 12.8s) | C | 60 | 19.0 |
8698 | 2025-07-15 17:18:46 | MASTER-SAAO | (13h 38m 42.15s , +39d 07m 59.9s) | C | 60 | 19.0 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.