[vsnet-grb-info 2403] GRB 051109A: KAIT optical observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4240
SUBJECT: GRB 051109A: KAIT optical observations
DATE:    05/11/10 05:42:17 GMT
FROM:    Weidong Li at UC Berkeley KAIT/LOSS  <weidong at astron.berkeley.edu>

W. Li, University of California, Berkeley, on behalf of the 
KAIT GRB team, report: 

We remotely observed GRB 051109A (Tagliaferri et al., GCN 4213)
with the 0.76-m Katzman Automatic Imaging Telescope (KAIT) at
Lick Observatory, and detected the afterglow (Rykoff et al., GCN 4211)
in a series of unfiltered exposures. The following photometry
are measured (calibrated to the USNO B1.0 catalog):

           Start UT  Exp(s)    mag     err

2005-11-09 02:25:48  120.0    18.67   0.04  
2005-11-09 02:28:28  120.0    18.73   0.06
2005-11-09 02:31:05  240.0    18.75   0.05
2005-11-09 02:35:37  240.0    18.82   0.04
2005-11-09 02:40:14  360.0    18.80   0.04
2005-11-09 02:46:48  360.0    18.88   0.04
2005-11-09 02:53:27  600.0    18.93   0.04

Within this period (74.5 to 106.1 minutes after the burst),
the afterglow declined with a power-law decay index of
-0.62 +/- 0.07, consistent with the result resported by Mirabal
et al. (GCN 4215).