TITLE: GCN CIRCULAR NUMBER: 7390 SUBJECT: GRB080310, optical observations with LBT DATE: 08/03/10 10:18:39 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 starting at 9:04 (UT) (0.44 hours after the burst) and ending 1 hour after the burst. Observations were obtained approximately every minute. The initial pair of observations showed no significant decay, but then declined rapidly into a power-law with a decay index of 0.65 (see Cobb et al., GCN 7386). This message may be cited.