[vsnet-grb-info 24865] GRB 200131A: CDK700 optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26964
SUBJECT: GRB 200131A: CDK700 optical observations
DATE:    20/02/02 21:01:36 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

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

We observed the field of the  GRB 200131A   (Sbarufatti al., GCN  26953) 
with CDK700 (0.7m) telescope  of Assy-Turgen observatory starting on 
Feb. 01  (UT) 14:58:49  in  R-filter.    We marginally detect the 
optical afterglow (Sbarufatti al., GCN  26953; Lipunov  al., GCN  26954; 
Butler al., GCN  26957; Strausbaugh al., GCN  26959; Kuin al., GCN  26962).

Preliminary photometry of the afterglow is following.

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

2019-02-01 14:58:49   0.76733     R    14*360  21.4 0.3   21.5

The photometry is based on nearby USNO-B1.0  stars  (R2 magnitudes).