TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  5043
SUBJECT: GRB 060501:  Refined analysis of the Swift-BAT burst
DATE:    06/05/01 15:56:31 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <Scott@lheamail.gsfc.nasa.gov>

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

Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 060501 (trigger #208050)  
(La Parola, et al., GCN 5040).  The BAT ground-calculated position is 
RA,Dec = 328.383,+43.993 deg {21h 53m 32.0s,+43d 59' 34.4"} (J2000)
+- 1.3 arcmin, (radius, sys+stat, 90% containment).  
The partial coding was 36%.

The mask-weighted lightcurve shows a single peak starting at T-4 sec and
ending at T+14 sec.  T90 (15-350 keV) is 26 +- 2 sec (estimated error
including systematics).  Because the burst location was in an Earth observing
constraint, the spacecraft then executed a slew to a preplanned target and
the new burst location went out of the BAT FOV at T+148 sec.

The time-averaged spectrum from T-1.3 to T+26.1 is best fit by 
a simple power-law model.  The power law index of the time-averaged 
spectrum is 1.44 +- 0.15.  The fluence in the 15-150 keV band is 
1.2 +- 0.1 x 10^-06 erg/cm2.  The 1-sec peak photon flux measured 
from T+0.36 sec in the 15-150 keV band is 1.9 +- 0.3 ph/cm2/sec.  
All the quoted errors are at the 90% confidence level.