TITLE: GCN CIRCULAR NUMBER: 27722 SUBJECT: IceCube Alert 200512.31: Global MASTER-Net observations report DATE: 20/05/12 18:13:10 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-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the IceCube Alert 200512.31 (trigger No 58268464,19h 40m 43.20s , +15d 47m 24.0s, R=1.63) errorbox 36576 sec after notice time and 36627 sec after trigger time at 2020-05-12 17:41:54 UT, with upper limit up to 12.3 mag. Observations started at twilight. The observations began at zenith distance = 43 deg. The sun altitude is -15.5 deg. The galactic latitude b = -4 deg., longitude l = 53 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1354761 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 36657 | 2020-05-12 17:41:54 | MASTER-Amur | (19h 46m 28.62s , +16d 07m 15.7s) | C | 60 | 12.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.