[vsnet-grb-info 6144] GRB 080524: Swift-BAT detection of a burst in ground analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7774
SUBJECT: GRB 080524: Swift-BAT detection of a burst in ground analysis
DATE:    08/05/25 19:41:39 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <jayc at milkyway.gsfc.nasa.gov>

G. Sato (GSFC/ISAS), L. Barbier (GSFC), S. Barthelmy (GSFC),
W. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU),
D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), M. Koss (GSFC/UMD),
C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),
T. Sakamoto (GSFC/ORAU), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
on behalf of the Swift-BAT team:


At 04:13:00 UT on May 24, 2008, BAT triggered on GRB 080524. The onboard
processing found a source that was not significant enough to initiate a
burst response. Routine processing on the ground of failed triggers found
a significant source (9.7 sigma) at RA, Dec 268.449, +80.143 which is:

RA 17h 53m 47.7s (J2000)
Dec 80d 8m 35s (J2000)

with an uncertainty radius of 2.5 arcmin (90% containment). The source
was 58% coded.

T90 was 9 +- 2 sec. The peak count rate was 600 counts/sec (15-350 keV).
Using the data set from T-2 to T+8 sec, the mask-weighted light curve
shows a single roughly symmetrical peak.

The power-law index of the time averages spectrum is 1.1 +- 0.2. The
fluence in the 15-150 keV range from T-2 to T+8 sec was
(2.9 +- 0.5) x 10-07 ergs/cm2. The 1-sec peak flux was 0.4 +- 0.2
counts/cm2/sec. All uncertainties are 90% confidence.

Swift is executing a TOO to the position of this burst, and preliminary
XRT and UVOT results should be available in a few hours.