[vsnet-grb-info 10693] GRB 110708A: Lick observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12116
SUBJECT: GRB 110708A: Lick observations
DATE:    11/07/09 05:54:15 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley at astro.berkeley.edu>

D. A. Perley, K. Clubb, M. Ganeshalingam, M. Ellison, D. Cohen, and J. 
S. Bloom (UC Berkeley) report:

We observed the position of INTEGRAL GRB 110708A (Gotz et al., GCN 
12112) with the 1-meter Nickel telescope at Lick Observatory starting at 
07:30:18 UT, 2.78 hours after the trigger.  We acquired four exposures 
of 300 seconds each (20 minutes total integration) in the I-band filter.

The XRT position given by D'Elia et al. (GCN 12115) lies near the center 
of an asterism of five bright, nearby point-sources (one of which is 
inside the XRT error circle), all of which are also visible in USNO 
imaging and are likely Galactic stars.  There is a possible, marginal 
detection of a fainter source within the XRT error circle at:

RA=22:40:27.33, dec=+53:57:42.8 (J2000)

The approximate magnitude of this object, if real, is I~20.5 (calibrated 
relative to USNO I-band).  It is fainter than the DSS limit and also too 
faint to clearly detect in individual exposures, so we cannot 
conclusively associate it with GRB 110708A at this time.

We identify no other objects within the XRT error circle to a limiting 
magnitude of I > 20.3, although the limit is complicated due to crowding 
from the nearby stars.