TITLE: GCN CIRCULAR NUMBER: 39049 SUBJECT: Fermi GRB 250127B: Global MASTER-Net observations report DATE: 25/01/27 18:46:18 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, 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. 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-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 250127B ( Fermi GBM team, GCN 39046) errorbox 8653 sec after notice time and 8678 sec after trigger time at 2025-01-27 17:39:17 UT, with upper limit up to 17.4 mag. The observations began at zenith distance = 79 deg. The sun altitude is -31.2 deg. The galactic latitude b = 13 deg., longitude l = 241 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2757386 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 8709 | 2025-01-27 17:39:17 | MASTER-Tavrida | (08h 26m 29.18s , -13d 05m 34.9s) | C | 60 | 17.4 | 9585 | 2025-01-27 17:53:53 | MASTER-Tavrida | (08h 26m 26.09s , -13d 07m 38.9s) | C | 60 | 17.0 | 9659 | 2025-01-27 17:55:07 | MASTER-Tavrida | (08h 21m 05.82s , -14d 24m 11.6s) | C | 60 | 17.0 | 9733 | 2025-01-27 17:56:21 | MASTER-Tavrida | (08h 29m 21.40s , -14d 25m 09.7s) | C | 60 | 17.2 | 9885 | 2025-01-27 17:58:53 | MASTER-Tavrida | (08h 13m 21.91s , -15d 42m 30.9s) | C | 60 | 17.0 | 9960 | 2025-01-27 18:00:08 | MASTER-Tavrida | (08h 21m 46.42s , -15d 43m 06.4s) | C | 60 | 16.8 | 10188 | 2025-01-27 18:03:56 | MASTER-Tavrida | (08h 26m 28.97s , -13d 06m 24.3s) | C | 60 | 16.9 | 10262 | 2025-01-27 18:05:10 | MASTER-Tavrida | (08h 21m 06.32s , -14d 26m 13.7s) | C | 60 | 16.7 | 10345 | 2025-01-27 18:06:33 | MASTER-Tavrida | (08h 29m 24.09s , -14d 24m 04.8s) | C | 60 | 16.7 | 10498 | 2025-01-27 18:09:06 | MASTER-Tavrida | (08h 13m 22.35s , -15d 42m 47.7s) | C | 60 | 16.8 | 10573 | 2025-01-27 18:10:21 | MASTER-Tavrida | (08h 21m 46.78s , -15d 43m 23.2s) | C | 60 | 16.5 | 10810 | 2025-01-27 18:14:18 | MASTER-Tavrida | (08h 26m 29.19s , -13d 06m 37.1s) | C | 60 | 16.4 | 10886 | 2025-01-27 18:15:34 | MASTER-Tavrida | (08h 21m 06.55s , -14d 26m 28.9s) | C | 60 | 16.4 | 10969 | 2025-01-27 18:16:57 | MASTER-Tavrida | (08h 29m 24.38s , -14d 24m 13.0s) | C | 60 | 16.4 | 11120 | 2025-01-27 18:19:28 | MASTER-Tavrida | (08h 13m 22.91s , -15d 43m 04.6s) | C | 60 | 16.4 | 11203 | 2025-01-27 18:20:51 | MASTER-Tavrida | (08h 21m 47.60s , -15d 43m 39.9s) | C | 60 | 16.1 | 11430 | 2025-01-27 18:24:38 | MASTER-Tavrida | (08h 26m 29.38s , -13d 06m 49.0s) | C | 60 | 15.6 | 11504 | 2025-01-27 18:25:52 | MASTER-Tavrida | (08h 21m 06.72s , -14d 26m 40.9s) | C | 60 | 15.4 | 11579 | 2025-01-27 18:27:07 | MASTER-Tavrida | (08h 29m 26.07s , -14d 24m 28.8s) | C | 60 | 15.6 | 11739 | 2025-01-27 18:29:47 | MASTER-Tavrida | (08h 13m 23.62s , -15d 43m 22.1s) | C | 60 | 16.2 | 11814 | 2025-01-27 18:31:02 | MASTER-Tavrida | (08h 21m 47.72s , -15d 43m 57.5s) | C | 60 | 15.6 | 12055 | 2025-01-27 18:35:03 | MASTER-Tavrida | (08h 26m 29.58s , -13d 06m 57.8s) | C | 60 | 16.7 | 12130 | 2025-01-27 18:36:18 | MASTER-Tavrida | (08h 21m 06.92s , -14d 26m 52.0s) | C | 60 | 16.6 | 12204 | 2025-01-27 18:37:32 | MASTER-Tavrida | (08h 29m 25.66s , -14d 25m 12.6s) | C | 60 | 16.4 | 12373 | 2025-01-27 18:40:21 | MASTER-Tavrida | (08h 13m 22.75s , -15d 43m 40.8s) | C | 60 | 17.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.