TITLE:   GCN CIRCULAR
NUMBER:  28202
SUBJECT: GRB 200803A: MASTER optical counterpart discovery
DATE:    20/08/03 17:12:31 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(Lomonosov Moscow State University, SAI, Physics Department),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
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),
V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational StateUniversity)


MASTER Global Robotic Net inspected GRB 200803A
(MASTER Lipunov et al. GCN 28198, Fermi LAT GCN 28199)
The result is optical counterpart discovery with classical OT decay

MASTER OT J204422.34-625641.8 discovery

MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic 
Net", Advances in Astronomy, 2010, 30L ) discovered OT source at
(RA, Dec) = 20h 44m 22.34s -62d 56m 41.8s on 2020-08-03.15015 UT.

The OT unfiltered magnitude is 15.8m (mlim=17.7).

The OT is seen in 13 images. There is no minor planet at this place.

We have reference image on 2015-04-04.15164 UT with  unfiltered mlim= 19.9m.

Spectral observations are required.