TITLE: GCN CIRCULAR NUMBER: 28001 SUBJECT: IceCube Alert 200620.13: Global MASTER-Net observations report DATE: 20/06/20 17:13:09 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the IceCube Alert 200620.13 (trigger No 33533447,10h 48m 26.40s , +11d 57m 00.0s, R=0.68) errorbox 48529 sec after notice time and 48560 sec after trigger time at 2020-06-20 16:32:52 UT, with upper limit up to 18.4 mag. Observations started at twilight. The observations began at zenith distance = 46 deg. The sun altitude is -10.7 deg. The galactic latitude b = 58 deg., longitude l = 236 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1386385 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 48650 | 2020-06-20 16:32:52 | MASTER-SAAO | (10h 50m 30.09s , +12d 04m 20.6s) | C | 180 | 18.4 | 48650 | 2020-06-20 16:32:52 | MASTER-SAAO | (10h 43m 31.72s , +12d 03m 09.6s) | C | 180 | 18.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.