[vsnet-grb-info 4422] GRB 070311: Optical Brightening

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6203
SUBJECT: GRB 070311: Optical Brightening
DATE:    07/03/13 16:23:43 GMT
FROM:    Jules Halpern at Columbia U.  <jules at 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 third consecutive night using the MDM 1.3m
telescope.  A combined 7x600 s image with mid-epoch
Mar. 13 03:10 UT shows that the OT has brightened by 0.88
mag since the previous night, reported in GCN 6199.
We measure R = 22.17 +/- 0.06 at 49.3 hours post burst,
using the same comparison star as in GCN 6195.
Considering that this location suffers 2.0 magnitudes of
Galactic extinction in the R band, it is possible that this
burst is at low redshift, and that the brightening represents
the onset of a supernova.  Spectroscopy to determine its
redshift and to search for a supernova are urged, as well
as continued photometry.

MDM images are posted at

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

This message may be cited."