GCN Circular 7528

A. Henden (AAVSO) reports:

While the field of GRB080319B has been observed by SDSS, we have also
obtained a four-night BVRcIc field calibration using the 35cm robotic
telescope at Sonoita Research Observatory.  The calibration file
has a limiting magnitude around V=16, with good standards brighter
than V=11 or so.  The file is available at
ftp://ftp.aavso.org/public/calib/grb/grb080319b.dat

This calibration is based on numerous Landolt standards, and has
an external zeropoint error of about 0.02mag. We are continuing
calibration of this field, moving to the west to pick up the
9th magnitude star SAO 64192, and will extend the calibration
file when that photometry is available.  Our system is available
for any other bright BVRI calibrations (4<V<19) for this field or any
other field; contact the author for such requests.

The AAVSO thanks the Curry Foundation for their continued support of the
AAVSO International High Energy Network.