TITLE: GCN CIRCULAR NUMBER: 30930 SUBJECT: Swift GRB211010.45: Global MASTER-Net observations report DATE: 21/10/10 17:42:09 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> 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), 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-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB211010.45 (trigger No 1078701,19h 08m 19.20s , +29d 49m 19.2s, R=0.05) errorbox 16730 sec after notice time and 16773 sec after trigger time at 2021-10-10 15:22:09 UT, with upper limit up to 18.8 mag. Observations started at twilight. The observations began at zenith distance = 14 deg. The sun altitude is -9.1 deg. MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB211010.45 errorbox 18827 sec after notice time and 18871 sec after trigger time at 2021-10-10 15:57:06 UT, with upper limit up to 18.9 mag. Observations started at twilight. The observations began at zenith distance = 15 deg. The sun altitude is -9.6 deg. The galactic latitude b = 9 deg., longitude l = 62 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1747849 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 16864 | MASTER-Kislovodsk | C | 180 | 15.0 | 16864 | MASTER-Kislovodsk | C | 180 | 17.5 | 18961 | MASTER-Tavrida | C | 180 | 16.7 | 19625 | MASTER-Kislovodsk | C | 180 | 18.4 | 19625 | MASTER-Kislovodsk | C | 180 | 18.6 | 20772 | MASTER-Tavrida | C | 180 | 18.9 | 21614 | MASTER-Kislovodsk | C | 180 | 18.5 | 21614 | MASTER-Kislovodsk | C | 180 | 18.8 | 21830 | MASTER-Tavrida | C | 180 | 18.7 | 22200 | MASTER-Tavrida | C | 180 | 18.6 | 22646 | MASTER-Tavrida | C | 180 | 18.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.