TITLE:   GCN CIRCULAR
NUMBER:  24060
SUBJECT: Fermi TriggNum 576054086 (GRB 1904204.29) / MASTER OT J071404.52+550304.2: CrAO optical observations
DATE:    19/04/08 14:04:12 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), V. Rumyantsev (CrAO),  A. Pozanenko (IKI),   E. Mazaeva 
(IKI),  A. Volnova (IKI) report on behalf of larger GRB follow-up 
collaboration:

We observed the field of the Fermi TriggNum 576054086 (Fermi GRB 
1904204.29) with ZTSH 2.6m telescope of CrAO observatory starting on 
Apr. 7 (UT) 19:01:27.   At the position of the optical transient MASTER 
OT J071404.52+550304 (Lipunov et al. GCN 24058) we  detect  the object.

Preliminary photometry of the object in R- filter is following

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

2019-04-07 19:01:27   3.04834 R      30*120    22.0  0.15  23.4


The photometry is based on nearby  USNO-B1.0 stars:

Ref.stars
USNO-B1.0_id    R2
1450-0176813    16.94
1450-0176812    18.46
1450-0176771    16.0

At present time we cannot confirm variability of the object. The object 
might be the afterglow or a host galaxy of the Fermi GRB 1904204.29 
(TriggNum 576054086).