GCN Circular 7423

G. Wegner (Dartmouth), P. Garnavich (Notre Dame), J. L. Prieto,
and K. Z. Stanek (OSU) report:

We observed the position of GRB 080310 (Chornock et al. GCN 7381
Not found
 
 
;
Cummings et al., GCN 7382
Not found
 
 
) with the Large Binocular Telescope
(LBC red and blue cameras) on March 13.40 (UT) and with the
MDM 2.4-m Hiltner telescope (Retrocam) on March 14.39 (UT) through
Sloan-r filters.

Using stars calibrated by the SDSS, we estimate the following
r-band magnitudes:

age (days)  r mag   error   telescope
3.04        22.45    0.05     LBT
4.03        23.10    0.10     MDM

The photometry indicates that the afterglow has resumed a steep
decline. Including LBT photometry from March 12 (Garnavich et al.,
GCN 7414
Not found
 
 
), we estimate a power-law decline index of 2.1 between
2 and 4 days after the burst.

A plot of the light curve is available at:
http://www.nd.edu/~pgarnavi/LBT/grb080310/LBT_lightcurve.jpg

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

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