NASA SWIFT: GRB 050802: Swift Gamma-ray Burst

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 3734
SUBJECT: GRB 050802: Swift Gamma-ray Burst
DATE: 05/08/02 11:53:01 GMT
FROM: David L. Band at NASA/GSFC dband@lheapop.gsfc.nasa.gov

D. Band (GSFC-UMBC), C. Markwardt (GSFC-UMD), M. Perri (ASDC), K. McGowan (MSSL), C. Gronwall (PSU), K. Page (U. Leicester), J. Racusin (PSU), D. Burrows (PSU), N. Gehrels (GSFC), J. Kennea (PSU), report on behalf of the Swift Team:

At 10:08:02 UT, Swift-BAT triggered and located GRB050802 (trigger=148646). The spacecraft slewed immediately. The BAT on-board calculated location is RA,Dec 219.287, +27.806 {+14h 37m 09s, +27d 48′ 23″} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The BAT light curve has a total duration of ~20 sec. The peak count rate was ~2000 counts/sec (15-350 keV).

The XRT began observing at 10:12:51 UT, 289 seconds after the BAT trigger. XRT was unable to centroid on any source, however the downlinked lightcurve and raw spectrum show a bright variable source is present in the XRT field of view. There are no catalogued X-ray sources in the field, suggesting that this bright source is the GRB afterglow.

Swift-UVOT began observations after the slew, however, the UVOT dark burst image did not come down via TDRSS so no information is available at this time. Detailed analysis will be performed when data is available after the next Malindi pass.

[GCN OPS NOTE(02aug05): Per author’s request, The “05080” in the Subject-line was changed “050802”.]