[vsnet-grb-info 5224] GRB 071010B: Keck/LRIS Photometry

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6919
SUBJECT: GRB 071010B: Keck/LRIS Photometry
DATE:    07/10/16 00:12:18 GMT
FROM:    Daniel Kocevski at UC Berkeley  <kocevski at berkeley.edu>

D. Kocevski, D. A. Perley, J. S. Bloom, M. Modjaz, and D. Poznanski  
(UC Berkeley)
report:

"In addition to the spectroscopic followup reported by Prochaska et  
al. (GCN 6890), we acquired a 90s exposure in R band and a 30s  
exposure in g and V bands of the field containing GRB 071010B with  
the Keck I 10m telescope (+LRIS), beginning at 15:01:21 UT on  
2007-10-11.  The optical afterglow at 10:02:9.26, +45:43:50.3  
reported by Oksanen et al. (GCN 6871) and confirmed by Kann et al.  
(GCN 6884 ) was clearly detected.  Using aperture photometry, we  
estimate the multi-color magnitudes of the afterglow to be:

R = 19.62
V = 19.71
g = 19.10

when calibrated to Landolt standard star observations.  We note that  
the afterglow had not faded considerably from the magnitude reported  
by Im et al. (GCN 6897) whose observations began approximately 4  
hours earlier.