A. Parsons (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC),
E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (UMD), S.
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL),
T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Suzuki (Saitama),
J. Tueller (GSFC) D. Burrows, J. Kennea, J. Nousek (PSU), G.
P. Romano (INAF-OAB)
on behalf of the Swift team:
At 15:58:48.40 UT Swift-BAT triggered on burst GRB 050406 (trigger
The BAT-derived position is RA,Dec= 34.428, -50.178 (J2000).
has been detected for at least 3 sec with possible low significance
an additional 30 sec. The peak count rate was 800 cnts/sec. The source
detected at 15 degrees off the bore-site and thus is in the fully-coded
Swift slewed promptly and the UVOT imaged the field at the end of the
slew and did
not find a bright optical source in the 8 arcmin square binned field of
on the BAT position.
The XRT also imaged the field promptly and did not find a bright X-ray
the field of view. Based on previous experience, this lack of prompt
suggests either that this trigger is not a GRB, or that it is a very
unusual GRB. The BAT rate trigger and image are significant enough to
toward an interpretation of an unusual GRB.