[vsnet-grb-info 6410] GRB 080727B: KAIT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8024
SUBJECT: GRB 080727B: KAIT observations
DATE:    08/07/27 10:03:20 GMT
FROM:    Weidong Li at UC Berkeley KAIT/LOSS  <weidong at astron.berkeley.edu>

W. Li, R. Chornock, D. A. Perley, J. S. Bloom, and A. V. Filippenko,
University of California at Berkeley, on behalf of the KAIT
GRB team, report:

The robotic 0.8-m KAIT located at Lick Observatory responded to
GRB 080727B (Immler et al. GCN 8022) automatically on July 27 
starting at 08:14:12 UT (48 seconds after the burst). A series of 
images were taken in the V, I, and clear filters. We detected a
fading new object at the following location:

RA  (J2000) =  18h27m26.05s   +/- 0.3"
Dec (J2000) = +01d09'47.7"    +/- 0.3" , 

suggesting that this is the optical afterglow of the GRB. 
We report the following preliminary photometry (calibrated
to USNO B1): 

UT start  exptime  filter     mag     err

08:14:12  2 s      clear   18.20    0.16
08:14:17  2 s      clear   18.38    0.16
08:14:20  2 s      clear   18.45    0.23

The power-law decay index between t = 49 s and 72 s after the 
burst is -1.44 +/- 0.59. Further analysis is ongoing.