GCN Circular 3900
Subject
GRB 050827: Optical Limit
Event
Date
2005-08-28T20:04:21Z (20 years ago)
From
Jules Halpern at Columbia U. <jules@astro.columbia.edu>
J. P. Halpern (Columbia U.) reports on behalf of the MDM Observatory
GRB follow-up team:
"I observed the error box of GRB 050827 (Swift trigger #152325, GCN #3893)
in the R band with the MDM 1.3m telescope for 50 minutes starting on
Aug. 28 09:32 UT, or 14.6 hours after the burst. There is no optical
object to a limiting magnitude R=23.5 within 16", or twice the error circle
radius, of the XRT candidate afterglow reported by Capalbi et al. (GCN #3899).
Even after correcting this limit for Galactic absorption A(R)=1.47 mag at its
location (Schlegel et al. 1988), it would be unusual for a persistent X-ray
source of flux 1.0E-12 erg cm^-2 s^-1 to have no optical counterpart. So
this supports the identification of the X-ray source as the GRB afterglow."