TITLE: GCN CIRCULAR NUMBER: 42029 SUBJECT: Fermi GRB 250929A: Global MASTER-Net observations report DATE: 25/09/29 20:31:09 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs lipunov@xray.sai.msu.ru
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 250929A ( Fermi GBM team, GCN 42028) errorbox 364 sec after notice time and 395 sec after trigger time at 2025-09-29 20:12:42 UT, with upper limit up to 18.9 mag. The observations began at zenith distance = 53 deg. The sun altitude is -42.7 deg.
The galactic latitude b = -45 deg., longitude l = 273 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3002549
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________
425 | 2025-09-29 20:12:42 | MASTER-SAAO | (02h 49m 40.43s , -53d 58m 56.7s) | C | 60 | 18.9 | 425 | 2025-09-29 20:12:42 | MASTER-SAAO | (02h 52m 46.96s , -54d 14m 04.8s) | C | 60 | 18.9 | Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
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