TITLE: GCN CIRCULAR NUMBER: 32268 SUBJECT: Fermi GRB 220623B: Global MASTER-Net observations report DATE: 22/06/25 03:15:44 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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 220623B ( Fermi GBM team, GCN 32249) errorbox 1 days 36625 sec after notice time and 1 days 36660 sec after trigger time at 2022-06-25 01:44:57 UT, with upper limit up to 15.2 mag. The observations began at zenith distance = 79 deg. The sun altitude is -51.2 deg. The galactic latitude b = 61 deg., longitude l = 91 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2013845 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 123091 | 2022-06-25 01:44:57 | MASTER-OAFA | (14h 18m 37.96s , +46d 12m 54.9s) | C | 60 | 13.2 | 123182 | 2022-06-25 01:46:28 | MASTER-OAFA | (14h 30m 27.39s , +46d 11m 45.4s) | C | 60 | 14.3 | 123365 | 2022-06-25 01:49:31 | MASTER-OAFA | (14h 22m 37.30s , +44d 17m 08.1s) | C | 60 | 15.1 | 123456 | 2022-06-25 01:51:02 | MASTER-OAFA | (14h 40m 59.56s , +46d 12m 28.2s) | C | 60 | 13.9 | 123547 | 2022-06-25 01:52:33 | MASTER-OAFA | (14h 32m 42.08s , +44d 18m 51.9s) | C | 60 | 15.0 | 124384 | 2022-06-25 02:06:30 | MASTER-OAFA | (14h 40m 59.88s , +46d 12m 07.3s) | C | 60 | 15.0 | 125523 | 2022-06-25 02:25:29 | MASTER-OAFA | (14h 32m 47.38s , +44d 16m 53.1s) | C | 60 | 15.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.