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GCN Circular 6203

GRB 070311: Optical Brightening
2007-03-13T16:23:43Z (17 years ago)
Jules Halpern at Columbia U. <>
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

This message may be cited."
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