TITLE: GCN CIRCULAR NUMBER: 31840 SUBJECT: IceCube Alert 220405.93: Global MASTER-Net observations report DATE: 22/04/06 02:39:31 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, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (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), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (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 220405.93 (trigger No 15341152,21h 21m 05.52s , +29d 16m 26.4s, R=0.57) errorbox 205 sec after notice time and 253 sec after trigger time at 2022-04-05 22:24:16 UT, with upper limit up to 17.5 mag. The observations began at zenith distance = 85 deg. The sun altitude is -39.0 deg. The galactic latitude b = -15 deg., longitude l = 78 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1934534 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 278 | 2022-04-05 22:24:16 | MASTER-Tavrida | (21h 10m 41.06s , +29d 20m 08.8s) | P\ | 50 | 14.1 | 442 | 2022-04-05 22:26:45 | MASTER-Tavrida | (21h 10m 38.14s , +29d 20m 14.9s) | P\ | 80 | 14.7 | 701 | 2022-04-05 22:30:39 | MASTER-Tavrida | (21h 10m 45.42s , +29d 18m 21.1s) | P\ | 130 | 14.4 | 860 | 2022-04-05 22:33:08 | MASTER-Tavrida | (21h 10m 47.13s , +29d 19m 16.8s) | P\ | 150 | 14.6 | 1045 | 2022-04-05 22:35:58 | MASTER-Tavrida | (21h 10m 52.69s , +29d 18m 09.4s) | P\ | 180 | 14.8 | 1244 | 2022-04-05 22:39:17 | MASTER-Tavrida | (21h 10m 48.09s , +29d 17m 04.5s) | P\ | 180 | 15.0 | 1444 | 2022-04-05 22:42:37 | MASTER-Tavrida | (21h 10m 54.31s , +29d 17m 03.1s) | P\ | 180 | 15.1 | 1643 | 2022-04-05 22:45:56 | MASTER-Tavrida | (21h 10m 51.07s , +29d 18m 55.0s) | P\ | 180 | 15.1 | 2921 | 2022-04-05 23:08:14 | MASTER-Tavrida | (21h 11m 46.38s , +29d 43m 16.3s) | C | 60 | 17.5 | 3900 | 2022-04-05 23:24:33 | MASTER-Tavrida | (21h 11m 54.18s , +29d 43m 52.9s) | C | 60 | 13.6 | 7168 | 2022-04-06 00:19:01 | MASTER-Tavrida | (21h 19m 24.68s , +31d 37m 22.4s) | C | 60 | 15.5 | 14033 | 2022-04-06 02:12:26 | MASTER-Tavrida | (21h 12m 01.83s , +29d 05m 55.1s) | P\ | 180 | 16.2 | 14232 | 2022-04-06 02:15:45 | MASTER-Tavrida | (21h 12m 00.56s , +29d 06m 58.0s) | P\ | 180 | 16.1 | 14432 | 2022-04-06 02:19:05 | MASTER-Tavrida | (21h 12m 07.54s , +29d 05m 59.7s) | P\ | 180 | 16.0 | 14632 | 2022-04-06 02:22:25 | MASTER-Tavrida | (21h 12m 01.54s , +29d 05m 01.3s) | P\ | 180 | 15.8 | 14771 | 2022-04-06 02:25:44 | MASTER-Tavrida | (21h 13m 49.18s , +27d 51m 07.0s) | C | 60 | 17.0 | 14930 | 2022-04-06 02:28:23 | MASTER-Tavrida | (21h 22m 54.58s , +27d 50m 38.8s) | C | 60 | 16.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.