TITLE: GCN CIRCULAR NUMBER: 31671 SUBJECT: IceCube Alert 220303.75: Global MASTER-Net observations report DATE: 22/03/04 02:39:16 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina, A.Chasovnikov, V.Topolev, V.Grinshpun, 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 (Irkutsk State University, API), B.L.Carrasco, J.R.Valdes,V.Chavushyan, C.J.Martinez, V.M.Patino Alvarez, M.L.H.Rodriguez (INAOE, OAGH) A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (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 IceCube Alert 220303.75 (trigger No 7450363,17h 49m 35.52s , +10d 59m 16.8s, R=0.55) errorbox 29480 sec after notice time and 29559 sec after trigger time at 2022-03-04 02:12:46 UT, with upper limit up to 17.6 mag. The observations began at zenith distance = 82 deg. The sun altitude is -64.6 deg. The galactic latitude b = 18 deg., longitude l = 36 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1901023 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 29649 | 2022-03-04 02:12:46 | MASTER-IAC | (17h 45m 15.18s , +11d 29m 54.6s) | C | 180 | 16.8 | 29849 | 2022-03-04 02:16:06 | MASTER-IAC | (17h 45m 22.83s , +11d 28m 50.7s) | C | 180 | 17.2 | 30049 | 2022-03-04 02:19:26 | MASTER-IAC | (17h 45m 16.07s , +11d 27m 49.0s) | C | 180 | 17.4 | 30249 | 2022-03-04 02:22:46 | MASTER-IAC | (17h 45m 22.84s , +11d 28m 02.4s) | C | 180 | 17.5 | 30449 | 2022-03-04 02:26:06 | MASTER-IAC | (17h 45m 20.10s , +11d 29m 32.7s) | C | 180 | 17.5 | 30648 | 2022-03-04 02:29:26 | MASTER-IAC | (17h 45m 20.22s , +11d 27m 54.2s) | C | 180 | 17.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.