[vsnet-grb-info 5232] GRB071013: optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6925
SUBJECT: GRB071013: optical observations
DATE:    07/10/16 18:57:43 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

G. Kornienko, A. Erofeeva (UAFO), A. Pozanenko (IKI) on behalf of larger GRB 
follow up collaboration report:

We observed the error box of  GRB071013  (Marshall  et al., GCN 6907) on 
Oct.13 with SR-22 telescope of UAFO observatory. A set of 50 unfiltered 
images of 60 s exposure was obtained starting (UT) 12:33:04.  In images 
between 12:39:04 - 12:49:04 we observed an object at the position RA(J2000) 
= 18:37:49.1 Dec(J2000)= +33:50:25 with uncertainties of 3" in both 
coordinates. The object is not visible before and after this time 
(UT)12:39:04 - 12:49:04. The object is in refined BAT error circle (Palmer 
et al., GCN 6911). Based on nearby USNO-A2.0 stars we estimate brightness of 
the object as R~18.2.

The source of USNO-B1.0 1238-0299614  (RA(J2000)=18 37 48.84  Dec(J2000)= 
+33 50 26.7)  sits close  (or coincides) to our object and it has R2=19.6. 
The photometry of the source in deep TLS observation (Kann et al., GCN 6917) 
is R=19.5 (Kann, private communication). If the USNO-B1.0 1238-0299614 
source is a galaxy, then the afterglow may be masked of the galaxy in later 
times. At this time we cannot confirm the nature of  the found object and we 
encourage to refine observations at the same period (Xin et al., GCN 6908).

The message may be cited.