TITLE:   GCN CIRCULAR
NUMBER:  35109
SUBJECT: GRB 231118A: MASTER OT observation
DATE:    23/11/18 22:10:51 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>


V.Lipunov (Lomonosov MSU), D.Buckley (SAAO),
A.Kuznetsov, D.Vlasenko, P.Balanutsa, K.Zhirkov, E.Gorbovskoy, Ya.Kechin, Yu.Tselik,
N.Tiurina, I.Gorbunov, V.Vladimirov, D.Zimnukhov, V.Senik, V.Topolev, A.Yudin,
A.Chasovnikov, D.Cheryasov, A.Sosnovskij, A.Pozdnyakov, M.Gulyaev (Lomonosov MSU,SAI,PhysicsDepartment),
O.A. Gres, N.M. Budnev (Irkutsk State University, API),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
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 etal.,2010,Advances in Astronomy,2010,30L)
started Fermi (GCN 35100) and
Swift (Evans et al. GCN 35101, GCN 35104, GCN 35106) GRB 231118A error box observation at 2023-11-18 20:19:50 UT by MASTER-SAAO (Lipunov et  al. GCN 35107).

There is optical counterpart MASTER OT J001919.45-480224.7
 with m_OT=19.2m+-0.2m at 2023-11-18 20:26:40 and next 5 expositions (automatic, unfiltered, mlim=19.5), at Skynet position (discovered by Dutton et al. GCN 35103, GCN 35108)

Observations started at 70deg.altitude.

Observation and reduction will be continued.