[vsnet-grb-info 25346] GRB 200325B: MASTERt OT detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27446
SUBJECT: GRB 200325B: MASTERt OT detection
DATE:    20/03/26 12:13:10 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at 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 State
University)


MASTER OT J111012.51+274912.8 discovery - new OT inside Fermi GRB 200325B 
(trigger 606840801)

MASTER Global Robotic Net inspected GRB 200325B:
Fermi trigger 606840801, Ttr=2020-03-05 14:53:16 UT, GCN #27441,
MASTER report GCN #27442, MASTER map and OT position.
During inspection
MASTER-Kislovodsk auto-detection system ( Lipunov et al., "MASTER Global 
Robotic Net", Advances in Astronomy, 2010, 30L )
discovered new OT source at (RA, Dec) = 11h 10m 12.51s +27d 49m 12.8s on 
2020-03-25 16:21:15 UT.
The OT unfiltered magnitude is 16.1m (mlim=17.8).
The OT is seen in 2 inspect images
(MASTER has 2 tubes at each observatory and works with large error-fields 
like Fermi in open mode, that gives 8 square degrees, i.e. 2x4sq.deg.).
There is no minor planet at this place and no any sources in VIZIER 
database (22mag limit in POSS history).

We have reference images on 2010-03-13.87244 UT with unfiltered mlim= 
20.2m, on 2020-02-21 21:54:40UT with mlim=20.3.
Spectral observations are required.
The discovery and reference images are available at: 
http://master.sai.msu.ru/static/OT/111012.51274912.8.png