GRB 251005A
GCN Circular 42117
Subject
Swift GRB 251005A: Global MASTER-Net observations report
Date
2025-10-05T22:14:35Z (4 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) was pointed to the Swift GRB 251005A ( K. L. Page et al., GCN 42113) errorbox 21439 sec after notice time and 21469 sec after trigger time at 2025-10-05 22:04:43 UT, with upper limit up to 16.8 mag. The observations began at zenith distance = 82 deg. The sun altitude is -52.7 deg.
The galactic latitude b = -14 deg., longitude l = 185 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3007783
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
21560 | MASTER-SAAO | C | 180 | 16.8 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 42111
Subject
GRB 251005A: Fermi GBM Final Localization
Date
2025-10-05T09:53:14Z (4 days ago)
From
Utkarsh Pathak at IIT Bombay <utkarshpathak.07@gmail.com>
Via
Web form
The Fermi GBM team reports the detection of a likely LONG GRB
"At 05:27:08.25 UT on 05 October 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 251005A (trigger 781334833/251005227).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 227.84, Dec = 5.07 (J2000 degrees, equivalent to J2000 15h 11m, 5d 04'),
with a statistical uncertainty of 4.90 degrees.
The angle from the Fermi LAT boresight is 86 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251005227/quicklook/glg_skymap_all_bn251005227.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/bn251005227/quicklook/glg_healpix_all_bn251005227.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251005227/quicklook/glg_lc_medres34_bn251005227.gif"