GCN Circular 3530

J. P. Halpern (Columbia), J. Kemp (Joint Astronomy Centre and Columbia),
and N. Mirabal (U. Michigan), report on behalf of the MDM Observatory
GRB follow-up team:

We monitored the location of Swift GRB 050607 and its decaying X-ray
afterglow (Retter et al., GCN #3525; Pagani et al., GCN #3528) in the
R band with the MDM 2.4m telescope beginning 16 minutes after the
trigger, and extending to 2 hours.  Seeing was approximately 1.1".
The afterglow candidate discovered by Rhoads (GCN #3527) is present
in all of our images with 22.5 < R < 23, and appears to have faded.
However, it is difficult for us to characterize its variability at 
this stage in the analysis as there may also be extended emission.
If correct, this is the faintest optical afterglow detected at the
equivalent time (Berger et al., astro-ph/0502468), even taking into
account the 0.4 magnitudes of R-band Galactic absorption in this
direction.

Images are posted at http://www.astro.columbia.edu/~jules/grb/050607/