TITLE:   GCN CIRCULAR
NUMBER:  6208
SUBJECT: GRB 070311: MDM Optical Monitoring
DATE:    07/03/15 05:43:48 GMT
FROM:    Jules Halpern at Columbia U.  <jules@astro.columbia.edu>

J. P. Halpern & E. Armstrong (Columbia U.) report on behalf
of the MDM Observatory GRB follow-up team:

"We observed the afterglow of INTEGRAL GRB 070311 in the
R band on the fourth and fifth consecutive nights using
the MDM 1.3m telescope.  The new results are summarized
as follows (using the comparison star from GCN 6195):

       -----------------------------------------
       Date(UT)  t-t0(days) Exposure R(mag) +/-
       -----------------------------------------
       Mar 14.15    3.07     7x600s  22.65  0.07
       Mar 15.14    4.06     9x600s  23.62  0.13
       -----------------------------------------

These magnitudes are in agreement with observations of
Greco et al. (GCN 6204) and Kann, Filgas, & Hoegner
GCN (6206), which together show that the rebrightening
we reported in GCN 6203 peaked on day 2.  The afterglow
is now fading rapidly.

The lastest MDM images are posted at

http://www.astro.columbia.edu/~jules/grb/070311/

This message may be cited"