TITLE: GCN CIRCULAR NUMBER: 26588 SUBJECT: Swift GRB191226.02: Global MASTER-Net observations report DATE: 19/12/26 01:18:32 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB191226.02 (trigger No 946234,01h 08m 33.89s , -57d 05m 05.3s, R=0.05) errorbox 7 sec after notice time and 105 sec after trigger time at 2019-12-26 00:32:51 UT, with upper limit up to 19.9 mag. Observations started at twilight. The observations began at zenith distance = 28 deg. The sun altitude is -10.5 deg. The galactic latitude b = -60 deg., longitude l = 298 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1240059 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 116 | MASTER-OAFA | C | 20 | 16.5 | 151 | MASTER-OAFA | C | 90 | 17.4 | Coadd 381 | MASTER-OAFA | C | 550 | 18.9 | Coadd 172 | MASTER-OAFA | C | 30 | 16.8 | 238 | MASTER-OAFA | C | 40 | 17.0 | 315 | MASTER-OAFA | C | 50 | 17.2 | 395 | MASTER-OAFA | C | 210 | 18.2 | Coadd 406 | MASTER-OAFA | C | 70 | 17.6 | 517 | MASTER-OAFA | C | 90 | 18.0 | 648 | MASTER-OAFA | C | 110 | 18.2 | 808 | MASTER-OAFA | C | 430 | 19.3 | Coadd 805 | MASTER-OAFA | C | 140 | 18.5 | 997 | MASTER-OAFA | C | 180 | 18.9 | 1209 | MASTER-OAFA | C | 180 | 19.0 | 1389 | MASTER-OAFA | C | 540 | 19.9 | Coadd 1420 | MASTER-OAFA | C | 180 | 19.3 | 1631 | MASTER-OAFA | C | 180 | 19.5 | 1843 | MASTER-OAFA | C | 180 | 19.5 | 2054 | MASTER-OAFA | C | 180 | 19.6 | 2265 | MASTER-OAFA | C | 180 | 19.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.