[vsnet-grb-info 8962] GRB 100224A SHB found in ground analysis of BAT data

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10451
SUBJECT: GRB 100224A SHB found in ground analysis of BAT data
DATE:    10/02/25 20:00:59 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings at nasa.gov>

J. R. Cummings (GSFC/UMBC), H. A. Krimm (GSFC/USRA),
F. E. Marshall (NASA/GSFC), and D. M. Palmer (LANL)
report on behalf of the Swift team:

At 15:20:10 UTC, Swift-BAT rate-triggered on GRB 100224A (trigger#
413805).  No source was found on board.  A source was found in ground
analysis at RA, Dec 83.467, -7.994, which is

RA (J2000) = 05h 33m 52.1s
Dec (J2000) = -07d 59' 37"

with an estimated error of 3 arcmin (90% containment).

The burst had two main peaks, the first larger, at T+0.2 and T+0.5 sec,
the first about 0.1 sec long, the second about 0.3 sec long.

The spectrum is well fit by a simple powerlaw with a photon index of
0.98 +- 0.23.  The fluence (15-150 keV) from T+0.17 to T+0.625 sec
was 3.2 +- 2 x 10^-8 ergs/cm^2/sec (1 sigma error estimates).

Since the source was not detected onboard, there are no automated
products for this burst. Since the burst is old for a SHB, there
are currently no plans for Swift followup observations.