[vsnet-grb-info 5329] GRB 071028: SARA observations of variable source

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7017
SUBJECT: GRB 071028: SARA observations of variable source
DATE:    07/10/29 21:58:11 GMT
FROM:    Adria C. Updike at Clemson U  <aupdike at clemson.edu>

Adria C. Updike, Dieter H. Hartmann (Clemson University) and Gary D. 
Henson (ETSU) report on behalf of the Clemson GRB Follow-Up Team:

We observed the field of GRB 071028 (GCN 7012, Racusin et al.) with the 
0.9m SARA telescope on Kitt Peak beginning 15 hours and 25 minutes after 
the trigger.  Under variable cloud cover, we detect an apparently fading 
source within the BAT circle, but outside the revised XRT position (GCN 
7014, Racusin et al.), at RA=07:59:15.22, Dec=+21:28:32.052 (+/- 2 
arcsec, J2000).  This candidate source is approximately 0.5 arcmin to 
the SW of the revised XRT position.  In an hour of exposures, the source 
faded from R ~ 17 to beyond our detection limit (R limit ~ 18.5 in a 
single 120s exposure).  The source was calibrated relative to 10 field 
stars in the USNO B1.0 catalog.  The separation between the candidate OT 
and the revised XRT position makes this very unlikely to be the 
afterglow of GRB 071028.  Second epoch observations may be required to 
establish the nature of this source.

The SARA website can be found at http://astro.fit.edu/sara/sara.html .

This message may be cited.