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.