TITLE:   GCN CIRCULAR
NUMBER:  28826
SUBJECT: GRB 201104B: MASTER optical observation
DATE:    20/11/04 19:56:02 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, N.Tiurina, P.Balanutsa,A.Kuznetsov,K.Zhirkov, F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, A.Chasovnikov,A.Pozdnyakov,
V.Topolev, 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 (Irkutsk State University, API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov, Yu. Sergienko (Blagoveschensk Educational State University)

MASTER-SAAO started GRB 201104B (Sbarufatti  et al. GCN 28825, Ttrig=2020-11-04 17:33:46) observation by
MASTER-II (2x4sq.deg.) in 2020-11-04  19:14:43UT (unfiltered, manual pointing) 
and by
MASTER very wide field cameras (Lipunov et al. 2010, Advances in Astronomy,vol.2010, 30L),
started at 48deg. altitude in clouds (the sun altitude was -25deg)

There is no OT at Swift-XRT position with mlim=16.1 
Observation and reduction will continue.