TITLE: GCN CIRCULAR NUMBER: 28510 SUBJECT: IceCube Alert 200926.33: Global MASTER-Net observations report DATE: 20/09/27 00:39:09 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), 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-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) was pointed to the IceCube Alert 200926.33 (trigger No 53384881,06h 26m 17.52s , -04d 12m 18.0s, R=0.51) errorbox 59270 sec after notice time and 59334 sec after trigger time at 2020-09-27 00:23:06 UT, with upper limit up to 16.9 mag. The observations began at zenith distance = 66 deg. The sun altitude is -33.5 deg. The galactic latitude b = -7 deg., longitude l = 214 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1449387 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 59424 | 2020-09-27 00:23:06 | MASTER-Tavrida | (06h 25m 45.93s , -04d 10m 21.3s) | C | 180 | 14.1 | 59604 | 2020-09-27 00:23:06 | MASTER-Tavrida | (06h 25m 45.95s , -04d 10m 21.5s) | C | 540 | 16.9 | Coadd 59625 | 2020-09-27 00:26:26 | MASTER-Tavrida | (06h 25m 53.40s , -04d 11m 23.8s) | C | 180 | 16.4 | 59826 | 2020-09-27 00:29:47 | MASTER-Tavrida | (06h 25m 46.55s , -04d 12m 25.1s) | C | 180 | 16.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.