TITLE: GCN CIRCULAR NUMBER: 28012 SUBJECT: Fermi GRB 200623A: Global MASTER-Net observations report DATE: 20/06/23 05:30:13 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), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), 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-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) started inspect of the Fermi GRB 200623A ( Fermi GBM team, GCN 28011) errorbox 924 sec after notice time and 957 sec after trigger time at 2020-06-23 03:33:58 UT, with upper limit up to 18.8 mag. The observations began at zenith distance = 63 deg. The sun altitude is -27.3 deg. The galactic latitude b = 45 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1387999 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 988 | 2020-06-23 03:33:58 | MASTER-IAC | (15h 03m 20.96s , +60d 01m 51.3s) | C | 60 | 18.8 | 988 | 2020-06-23 03:33:58 | MASTER-IAC | (14h 46m 59.24s , +60d 06m 59.1s) | C | 60 | 18.3 | 1108 | 2020-06-23 03:35:59 | MASTER-IAC | (14h 53m 55.06s , +62d 00m 52.3s) | C | 60 | 18.5 | 1108 | 2020-06-23 03:35:59 | MASTER-IAC | (14h 36m 29.92s , +62d 06m 01.8s) | C | 60 | 18.2 | 1226 | 2020-06-23 03:37:56 | MASTER-IAC | (15h 12m 34.01s , +58d 01m 45.3s) | C | 60 | 18.6 | 1226 | 2020-06-23 03:37:56 | MASTER-IAC | (14h 57m 07.88s , +58d 06m 52.4s) | C | 60 | 18.3 | 1346 | 2020-06-23 03:39:56 | MASTER-IAC | (15h 03m 20.54s , +60d 00m 47.4s) | C | 60 | 18.7 | 1346 | 2020-06-23 03:39:56 | MASTER-IAC | (14h 46m 59.37s , +60d 05m 55.7s) | C | 60 | 18.5 | 1466 | 2020-06-23 03:41:56 | MASTER-IAC | (14h 53m 54.70s , +61d 59m 46.6s) | C | 60 | 18.5 | 1466 | 2020-06-23 03:41:56 | MASTER-IAC | (14h 36m 30.27s , +62d 04m 56.3s) | C | 60 | 18.2 | 1587 | 2020-06-23 03:43:57 | MASTER-IAC | (15h 12m 38.65s , +57d 59m 56.1s) | C | 60 | 18.6 | 1587 | 2020-06-23 03:43:58 | MASTER-IAC | (14h 57m 13.35s , +58d 05m 03.5s) | C | 60 | 18.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.