TITLE: GCN CIRCULAR NUMBER: 31946 SUBJECT: IceCube Alert 220425.11: Global MASTER-Net observations report DATE: 22/04/25 07:26:17 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-OAGH robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the IceCube Alert 220425.11 (trigger No 17854328,17h 53m 29.76s , -12d 18m 36.0s, R=1.11) errorbox 13769 sec after notice time and 13813 sec after trigger time at 2022-04-25 06:35:11 UT, with upper limit up to 17.6 mag. The observations began at zenith distance = 76 deg. The sun altitude is -44.8 deg. The galactic latitude b = 6 deg., longitude l = 16 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1953585 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 13844 | 2022-04-25 06:35:11 | MASTER-OAGH | (17h 48m 57.35s , -12d 30m 38.1s) | C | 60 | 17.3 | 13844 | 2022-04-25 06:35:11 | MASTER-OAGH | (17h 48m 17.45s , -12d 06m 51.7s) | C | 60 | 16.8 | 14127 | 2022-04-25 06:39:55 | MASTER-OAGH | (17h 56m 25.28s , -12d 06m 59.5s) | C | 60 | 16.4 | 14127 | 2022-04-25 06:39:55 | MASTER-OAGH | (17h 57m 05.48s , -12d 30m 44.6s) | C | 60 | 16.9 | 14888 | 2022-04-25 06:52:36 | MASTER-OAGH | (17h 48m 56.31s , -12d 29m 39.0s) | C | 60 | 17.5 | 14888 | 2022-04-25 06:52:36 | MASTER-OAGH | (17h 48m 17.87s , -12d 05m 50.4s) | C | 60 | 16.7 | 15133 | 2022-04-25 06:56:40 | MASTER-OAGH | (17h 56m 26.76s , -12d 06m 38.8s) | C | 60 | 16.7 | 15133 | 2022-04-25 06:56:40 | MASTER-OAGH | (17h 57m 05.52s , -12d 30m 28.9s) | C | 60 | 17.4 | 16107 | 2022-04-25 07:12:54 | MASTER-OAGH | (17h 48m 19.85s , -12d 05m 02.3s) | C | 60 | 15.9 | 16107 | 2022-04-25 07:12:54 | MASTER-OAGH | (17h 48m 56.45s , -12d 28m 52.4s) | C | 60 | 17.6 | 16552 | 2022-04-25 07:20:20 | MASTER-OAGH | (17h 56m 25.20s , -12d 07m 12.1s) | C | 60 | 15.6 | 16552 | 2022-04-25 07:20:20 | MASTER-OAGH | (17h 57m 01.27s , -12d 30m 45.5s) | C | 60 | 16.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.