TITLE: GCN CIRCULAR NUMBER: 31600 SUBJECT: GRB 220211A: MASTER optical observations of ZTF22aaajecp/AT2022cmc DATE: 22/02/16 22:39:20 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, A.Kuznetsov, P.Balanutsa, A.Chasovnikov, K.Zhirkov, O.Gress, N.Tiurina, G.Antipov, E.Gorbovskoy, D. Vlasenko, V.Senik, Ya.Kechin, V.Topolev (Lomonosov MSU,SAI,PhysicsDepartment), R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), N.M. Budnev (Irkutsk State University, API), C.Francile, R. Podesta, F. Podesta (OAFA), L. Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J. Martinez, A.R.Corella, L.H.Rodriguez (INAOE, OAGH), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) MASTER Global robotic net (MASTER-Net:http://observ.pereplet.ru Lipunov et al.,2010,Advances in Astronomy,2010,30L) started inspect of Fermi short GRB 200211A (Ttrigger=2022-02-11 01:07:48UT, GCN 31570 https://gcn.gsfc.nasa.gov/other/220211A.gcn3) 33 sec after notice time (64 sec after trigger time) at 2022-02-11 01:08:53 UT and observed it at MASTER-IAC, -Tavrida, -Amur, -Kislovodsk, -SAAO, -OAGH, see cover map in Lipunov et al. GCN 31571 https://master.sai.msu.ru/site/master2/observ.php?id=1878703 ) ZTF (Andreoni et al. GCN31590) discovered new OT at R.A.,Dec.=13:34:43.20,+33:13:00.44 (ZTF22aaajecp/AT2022cmc) on 2022-02-11 10:42 UT We are analyzing 1864 MASTER database images of these coordinates since 2006y up to now. Preliminary results of OT detections (unfiltered,calibrated by Gaia) are the following: Date, m_OT 2022-02-13.03UT 19.4 2017-11-14.85UT 17.8 2014-03-27.68UT 19.0 The analysis will be continued. Additional observations are planned.