Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 3085

GRB 050309, Early optical limits from RAPTOR
2005-03-11T00:57:16Z (19 years ago)
Przemyslaw R. Wozniak at LANL <>
P.R. Wozniak, S. Evans, W.T. Vestrand, R. White, J. Wren (LANL)
on behalf of the RAPTOR team. 

The RAPTOR A telescope responded to Swift-BAT trigger 107873 and began
optical imaging of the burst location in 6.7 seconds from the time
of receiving the alert (2.3 min. after GRB time). Photometry at the
locations of the two X-ray candidate counterparts to GRB 050309 reported
by Barthelmy et al. (GCN 3082) shows no optical emission in a series of
10 second exposures, each with the limiting magnitude R=15.0. A stack of
the first 10 images with the mean time of observation 4.2 min. after the
GRB time had a magnitude limit of R=16.1.
Looking for U.S. government information and services? Visit