TITLE:   GCN CIRCULAR
NUMBER:  7876
SUBJECT: GRB 080613B, Swift-BAT refined analysis
DATE:    08/06/13 18:41:44 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. Ukwatta (GWU), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD),
D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 080613B (trigger #313954)
(Markwardt, et al., GCN Circ. 7873).  The BAT ground-calculated position is
RA, Dec = 173.806, -7.102 deg, which is 
   RA(J2000)  =  11h 35m 13.3s 
   Dec(J2000) = -07d 06' 06.5" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 89%.
 
The mask-weighted light curve shows several overlapping peaks in a FRED-like
envelope lasting out to ~T+180 sec.  T90 (15-350 keV) is 105 +- 35 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-5.3 to T+236.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.39 +- 0.06.  The fluence in the 15-150 keV band is 5.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+2.23 sec in the 15-150 keV band
is 2.7 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/313954/BA/