TITLE: GCN CIRCULAR NUMBER: 7409 SUBJECT: GRB080310, optical observations with the LBT DATE: 08/03/11 14:23:35 GMT FROM: Peter Garnavich at U of Notre Dame P. Garnavich (Notre Dame), J. L. Prieto, R. Pogge (OSU) report: We observed the position of GRB 080310 (Chornock et al. GCN 7381; Cummings et al., GCN 7382) with the Large Binocular Telescope and LBC red and blue cameras on March 11 starting at 11:30 (UT) or 26.8 hours after the burst. On the red camera the images were taken through a Sloan-r filter and calibrating with the SDSS catalog (Cool et al.; GCN 7396) we find the brightness to be r=21.38+/-0.05 mag. Extrapolating the decay from LBT observations of March 10 (Prieto et al., GCN 7392) with an index of 1.15, the afterglow is about 0.2 mag brighter than expected. This could be due to host galaxy light or deviations from a single power-law decay. The LBT is an international collaboration among institutions in the United States, Italy and Germany. The LBT Corporation partners are: * The University of Arizona on behalf of the Arizona university system * Istituto Nazionale di Astrofisica, Italy * LBT Beteiligungsgesellschaft, Germany, representing the Max Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University * The Ohio State University * The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota and University of Virginia This message may be cited.