TITLE: GCN CIRCULAR NUMBER: 28157 SUBJECT: Fermi GRB 200723A: Global MASTER-Net observations report DATE: 20/07/23 17:30:26 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-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 200723A ( Fermi GBM team, GCN 28155) errorbox 61 sec after notice time and 87 sec after trigger time at 2020-07-23 16:36:52 UT, with upper limit up to 19.3 mag. The observations began at zenith distance = 12 deg. The sun altitude is -18.6 deg. The galactic latitude b = 33 deg., longitude l = 90 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1406982 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 98 | 2020-07-23 16:36:52 | MASTER-Tunka | (18h 25m 28.78s , +57d 41m 39.0s) | P| | 20 | 16.9 | 138 | 2020-07-23 16:37:33 | MASTER-Tunka | (17h 10m 07.98s , +60d 43m 48.8s) | P| | 20 | 17.3 | 182 | 2020-07-23 16:38:12 | MASTER-Tunka | (17h 10m 03.28s , +60d 42m 46.7s) | P| | 30 | 17.7 | 237 | 2020-07-23 16:39:01 | MASTER-Tunka | (17h 10m 09.23s , +60d 42m 45.4s) | P| | 40 | 17.8 | 301 | 2020-07-23 16:40:00 | MASTER-Tunka | (17h 10m 05.43s , +60d 44m 21.0s) | P| | 50 | 18.1 | 381 | 2020-07-23 16:41:10 | MASTER-Tunka | (17h 10m 05.24s , +60d 42m 58.8s) | P| | 70 | 18.4 | 465 | 2020-07-23 16:42:39 | MASTER-Tunka | (16h 54m 47.92s , +59d 52m 11.4s) | C | 60 | 19.3 | 581 | 2020-07-23 16:44:35 | MASTER-Tunka | (16h 52m 45.47s , +61d 52m 08.0s) | C | 60 | 18.9 | 690 | 2020-07-23 16:45:54 | MASTER-Tunka | (16h 36m 47.21s , +57d 55m 40.5s) | P| | 120 | 18.9 | 845 | 2020-07-23 16:48:14 | MASTER-Tunka | (16h 36m 53.38s , +57d 55m 51.2s) | P| | 150 | 19.0 | 1029 | 2020-07-23 16:51:03 | MASTER-Tunka | (16h 36m 49.68s , +57d 57m 08.3s) | P| | 180 | 19.0 | 1228 | 2020-07-23 16:54:22 | MASTER-Tunka | (16h 36m 49.18s , +57d 55m 45.7s) | P| | 180 | 19.0 | 1538 | 2020-07-23 17:00:33 | MASTER-Tunka | (16h 54m 46.63s , +59d 52m 54.7s) | C | 60 | 19.0 | 1619 | 2020-07-23 17:01:53 | MASTER-Tunka | (17h 10m 54.87s , +59d 51m 40.0s) | C | 60 | 19.0 | 1698 | 2020-07-23 17:03:13 | MASTER-Tunka | (16h 52m 36.95s , +61d 50m 49.9s) | C | 60 | 19.0 | 1778 | 2020-07-23 17:04:32 | MASTER-Tunka | (17h 09m 48.78s , +61d 50m 45.5s) | C | 60 | 19.1 | 2691 | 2020-07-23 17:19:45 | MASTER-Tunka | (17h 10m 50.96s , +59d 50m 26.8s) | C | 60 | 18.5 | 2771 | 2020-07-23 17:21:05 | MASTER-Tunka | (17h 09m 50.15s , +61d 50m 39.3s) | C | 60 | 19.1 | 2867 | 2020-07-23 17:22:42 | MASTER-Tunka | (17h 00m 03.82s , +58d 20m 47.8s) | C | 60 | 19.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.