[AAVSO-HEN] GRB 071010A: Continued Keck Imaging

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  6885
SUBJECT: GRB 071010A: Continued Keck Imaging
DATE:    07/10/11 15:11:26 GMT
FROM:    Daniel Kocevski at UC Berkeley  <kocevski at berkeley.edu>

D. Kocevski, D. A. Perley, and M. Modjaz (UC Berkeley) report:

Beginning at 04:47:42 UT (2007-10-11) we began a second series of  
imaging on the field of GRB 071010A (GCN 6733) using the Keck I  
telescope (+LRIS).  We acquired 6 images with an effective exposure  
of 270s in R band and 360s in V band.

The optical afterglow (GCN 6860) is still detected and has faded  
since our previous imaging epoch (GCN 6872).  Preliminary aperture  
photometry of the source indicates that it has faded by 0.55  
magnitudes since our previous imaging.  Using the same calibration  
system as in our previous circular, we estimate a preliminary  
magnitude of R=19.42