TITLE:   GCN CIRCULAR
NUMBER:  27599
SUBJECT: GRB 200415A: MASTER imspection and possible localisation 
DATE:    20/04/17 07:49:37 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, N.Tyurina,
E. Gorbovskoy, V.Kornilov, 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 OTJ 004724.94-252125.6s  (AT2020hok)

MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic
Net", Advances in Astronomy, 2010, 30L )
  proposed interesting  source at (RA, Dec) = 00h 47m 24.94s -25d 21m 25.6s
on  2020-04-17.15061 UT during GRB 200415 error box inspection 
(GCN  27579; 27580; 27586; 27595; 27597;).

Inside galaxy NGC 0253 (Svinkin, 27595; Frederiks 27597;) there 
is  an  interesting extended object with an XMM X-ray source  at 00 47 
25.0800 -25 21 23.760 .
This is may be globular cluster: B-V ~ 1
The  unfiltered magnitude is 15.8m (mlim 17.9).
The source  is seen in 24 images. No optical variability detected.

We have reference image on 2018-08-10.99113 UT with  unfiltered 
mlim=20.3m.

Follow up observations are required.

The cover map is available at
https://master.sai.msu.ru/site/master2/event.php?id=1337630

The inspection  and reference images are available at:

http://master.sai.msu.ru/static/OT/183315.33623157.0.png