TITLE: GCN CIRCULAR NUMBER: 26600 SUBJECT: Swift GRB191228.00: Global MASTER-Net observations report DATE: 19/12/28 00:10:10 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-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) was pointed to the Swift GRB191228.00 (trigger No 946476,00h 21m 21.36s , -08d 40m 12.0s, R=0.05) errorbox 146 sec after trigger time at 2019-12-28 00:03:46 UT, with upper limit up to 17.3 mag. The observations began at zenith distance = 82 deg. The sun altitude is -75.7 deg. The galactic latitude b = -70 deg., longitude l = 102 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1241866 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 157 | MASTER-IAC | P| | 20 | 16.9 | 208 | MASTER-IAC | P| | 40 | 17.3 | 265 | MASTER-IAC | P| | 50 | 17.3 | The observation and reduction will continue. The message may be cited.