[vsnet-grb-info 13700] GRB 130722A: Faulkes Telescope South optical candidate

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15015
SUBJECT: GRB 130722A: Faulkes Telescope South optical candidate
DATE:    13/07/22 10:07:51 GMT
FROM:    Andrea Melandri at Liverpool John Moores U  <axm at astro.livjm.ac.uk>

A. Melandri (INAF/OAB), C. Guidorzi (U. Ferrara), J. Japelj (U.  
Ljubljana), D. Kopac (U. Ljubljana), C.G. Mundell (LJMU) and A. Gomboc  
(U. Ljubljana) report:

The 2-m Faulkes Telescope South automatically began observing GRB  
130722A (Troja et al. GCN Circ. 15013) on July 22 2013 at 08:21:29 UT  
(~130 s after the burst trigger).

We find a fading object at coordinates

RA(2000.0)=   17:22:36.47
Dec(2000.0)= -02:58:21.6   (error 1.3")

with the following magnitudes

Mid time from  Total Exp   Filter    Magnitude
trigger (min)   (s)
--------------------------------------------------------------
12.37           1x30        R       18.0 +- 0.1
18.07           1x60        R       18.3 +- 0.1
--------------------------------------------------------------

Magnitudes are calibrated against nearby USNO-B1 stars, performing  
aperture photometry of the proposed optical counterpart above together  
with the nearby object located at RA(2000.0)=17:22:36.54,  
Dec(2000.0)=-02:58:22.1. The latter might be related to the OT, has a  
distance of 1.2" from the candidate and a catalogued magnitude of  
R2=19.7. It looks extended and might be the host galaxy of GRB 130722A.