[vsnet-grb-info 24773] GRB 200115A: Assy optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26872
SUBJECT: GRB 200115A: Assy optical observations
DATE:    20/01/24 17:57:09 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

A. Volnova (IKI), V. Kim (AFIF), A. Pozanenko (IKI), M. Krugov (AFIF), 
E. Mazaeva  (IKI), S. Belkin (IKI) report on behalf of larger GRB IKI 
FuN collaboration:

We observed the field of  GRB 200115A (Cenko et al.,  GCN 26771)  with 
AZT-20 1.5 m telescope  of Assy-Turgen observatory  starting on Jan. 18 
(UT) 16:55:27  in  r'-filter.   We do not detect the afterglow candidate 
(GCNs 26790, 26818) up to r'=22.8 (AB) and hence we consider the object 
found in BAT error circle (Cenko et al.,  GCN 26771) as the optical 
afterglow of GRB 200215A.

Photometry of the field is following.

Date       UT start   t-T0       Filter Exp.   OT   UL (3sigma)
                       (mid, days)        (s)

2019-10-18 16:55:27   3.22608     r'    13*180 n/d  22.8

The photometry is based on the nearby SDSS-DR12 stars.