TITLE: GCN CIRCULAR NUMBER: 42532 SUBJECT: Fermi GRB 251102A: Global MASTER-Net observations report DATE: 25/11/02 02:30:56 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs 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 251102A ( Fermi GBM team, GCN 42531) errorbox 28 sec after notice time and 63 sec after trigger time at 2025-11-02 02:04:49 UT, with upper limit up to 16.9 mag. The observations began at zenith distance = 47 deg. The sun altitude is -18.9 deg. MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 251102A errorbox 99 sec after notice time and 133 sec after trigger time at 2025-11-02 02:05:59 UT, with upper limit up to 18.5 mag. The observations began at zenith distance = 52 deg. The sun altitude is -24.5 deg. The galactic latitude b = 54 deg., longitude l = 122 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3030148 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 68 | 2025-11-02 02:04:49 | MASTER-Kislovodsk | (12h 52m 47.94s , +64d 29m 27.5s) | C | 10 | 15.1 | 69 | 2025-11-02 02:04:49 | MASTER-Kislovodsk | (13h 12m 42.94s , +64d 05m 30.2s) | C | 10 | 15.2 | 109 | 2025-11-02 02:05:29 | MASTER-Kislovodsk | (12h 52m 48.10s , +64d 29m 29.8s) | C | 10 | 15.0 | 115 | 2025-11-02 02:05:36 | MASTER-Kislovodsk | (13h 12m 42.91s , +64d 05m 32.1s) | C | 10 | 15.3 | 149 | 2025-11-02 02:05:59 | MASTER-Tavrida | (13h 10m 49.26s , +63d 40m 20.7s) | C | 30 | 16.0 | 150 | 2025-11-02 02:06:05 | MASTER-Kislovodsk | (12h 52m 48.12s , +64d 29m 32.0s) | C | 20 | 15.3 | 150 | 2025-11-02 02:06:05 | MASTER-Kislovodsk | (13h 12m 42.97s , +64d 05m 34.4s) | C | 20 | 15.6 | 199 | 2025-11-02 02:06:44 | MASTER-Tavrida | (13h 02m 23.04s , +63d 53m 59.4s) | C | 40 | 17.3 | 254 | 2025-11-02 02:06:44 | MASTER-Tavrida | (13h 02m 23.04s , +63d 53m 59.3s) | C | 150 | 18.4 | Coadd 195 | 2025-11-02 02:06:45 | MASTER-Kislovodsk | (12h 52m 48.13s , +64d 29m 35.6s) | C | 30 | 16.2 | 195 | 2025-11-02 02:06:45 | MASTER-Kislovodsk | (13h 12m 43.03s , +64d 05m 37.7s) | C | 30 | 16.3 | 249 | 2025-11-02 02:07:35 | MASTER-Kislovodsk | (12h 52m 48.13s , +64d 29m 39.1s) | C | 40 | 16.1 | 249 | 2025-11-02 02:07:35 | MASTER-Kislovodsk | (13h 12m 43.06s , +64d 05m 41.4s) | C | 40 | 16.2 | 255 | 2025-11-02 02:07:35 | MASTER-Tavrida | (13h 02m 22.99s , +63d 53m 58.1s) | C | 50 | 17.3 | 314 | 2025-11-02 02:08:30 | MASTER-Tavrida | (13h 02m 22.85s , +63d 53m 57.1s) | C | 60 | 17.5 | 314 | 2025-11-02 02:08:35 | MASTER-Kislovodsk | (12h 52m 48.15s , +64d 29m 42.9s) | C | 50 | 16.1 | 314 | 2025-11-02 02:08:35 | MASTER-Kislovodsk | (13h 12m 43.10s , +64d 05m 45.4s) | C | 50 | 16.6 | 394 | 2025-11-02 02:09:45 | MASTER-Kislovodsk | (12h 52m 48.21s , +64d 29m 47.4s) | C | 70 | 16.4 | 394 | 2025-11-02 02:09:45 | MASTER-Kislovodsk | (13h 12m 43.08s , +64d 05m 49.9s) | C | 70 | 16.9 | 398 | 2025-11-02 02:09:49 | MASTER-Tavrida | (13h 02m 22.62s , +63d 53m 55.9s) | C | 70 | 17.5 | 473 | 2025-11-02 02:09:49 | MASTER-Tavrida | (13h 02m 22.60s , +63d 53m 55.8s) | C | 220 | 18.5 | Coadd 502 | 2025-11-02 02:11:23 | MASTER-Tavrida | (13h 02m 22.27s , +63d 53m 54.9s) | C | 90 | 18.1 | 616 | 2025-11-02 02:13:07 | MASTER-Tavrida | (12h 53m 48.03s , +64d 07m 08.3s) | C | 110 | 17.9 | 624 | 2025-11-02 02:13:15 | MASTER-Kislovodsk | (12h 43m 41.31s , +63d 58m 15.7s) | C | 110 | 16.5 | 624 | 2025-11-02 02:13:15 | MASTER-Kislovodsk | (13h 03m 03.27s , +63d 33m 47.8s) | C | 110 | 16.8 | 759 | 2025-11-02 02:15:25 | MASTER-Kislovodsk | (12h 43m 41.35s , +63d 58m 20.8s) | C | 120 | 15.2 | 874 | 2025-11-02 02:17:49 | MASTER-Tavrida | (12h 37m 03.34s , +63d 40m 00.7s) | C | 60 | 16.4 | 943 | 2025-11-02 02:18:59 | MASTER-Tavrida | (13h 02m 20.04s , +63d 55m 18.8s) | C | 60 | 16.6 | 1012 | 2025-11-02 02:20:07 | MASTER-Tavrida | (13h 02m 14.69s , +63d 55m 45.5s) | C | 60 | 16.9 | 1102 | 2025-11-02 02:20:07 | MASTER-Tavrida | (13h 02m 14.66s , +63d 55m 45.5s) | C | 240 | 17.9 | Coadd 1080 | 2025-11-02 02:21:16 | MASTER-Tavrida | (13h 02m 13.43s , +63d 53m 45.0s) | C | 60 | 17.0 | 1178 | 2025-11-02 02:22:24 | MASTER-Tavrida | (13h 02m 16.73s , +63d 55m 29.1s) | C | 120 | 16.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.