TITLE:   GCN CIRCULAR
NUMBER:  6090
SUBJECT: GRB 070208: MARGE Optical Observations
DATE:    07/02/09 19:56:20 GMT
FROM:    Heather Swan at U.of Michigan/ROTSE  <hflewell@umich.edu>

H. Swan (U. Michigan), I. Smith (Rice), M. Skinner (AMOS Observatory,
Boeing LTS), R. Russell, (Aerospace Corporation),
report on behalf of the MARGE collaboration:

The AEOS Burst Camera (ABC) on the AEOS telescope located at the Maui 
Space Surveillance System on Haleakala Maui began imaging Swift 
GRB070208 (GCN 6074 Sato et al) on Feb 8, 2007 at 09:22:38.11 UTC, ~12 
minutes after the GRB was detected. These are unfiltered optical images. 
  After coadding our 10s images in sets of 10, we find the OT first 
identified by Guidorzi et al. (GCN 6077). Using the SDSS data provided 
by Cool et al (GCN 6080), we calibrate the OT to the r band magnitude of 
the star located at RA=197.89688 Dec=61.97785.  The approximate 
statistical errors are 0.2 magnitudes.  We report the following 
magnitudes for the OT:

time            ABC mag
09:22:38.11 UT  mag= 20.3
09:35:10.03 UT  mag= 20.3
09:59:46.08 UT  mag= 20.9
10:02:53.99 UT  mag= 20.8


The Rice University CCD Camera (RUCCD) on the AEOS telescope also
observed GRB 070208.  Ic-band images were taken between 2007-02-08
09:49 UT and 10:35 UT.  The results are consistent with the Palomar
observations of Fox et al. (GCN 6078).