TITLE:   GCN CIRCULAR
NUMBER:  16240
SUBJECT: GRB 140509A: Swift-BAT refined analysis
DATE:    14/05/09 17:41:50 GMT
FROM:    Jay R. Cummings at NASA/GSFC/Swift  <james.r.cummings@nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),  W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(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 140509A (trigger #598497) (Page, et al.,
GCN Circ. 16230).  The BAT ground-calculated position is
RA, Dec = 46.564, -62.662 deg which is
    RA(J2000)  =  03h 06m 15.3s
    Dec(J2000) = -62d 39' 43"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 19%.
  
The mask-weighted light curve shows a single FRED peak.  T90 (15-350 keV) is
23.20 +- 5.17 sec (estimated error including systematics).
  
The time-averaged spectrum from T-3.8 to T+23.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.59 +- 0.20.  The fluence in the 15-150 keV band is 1.2 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+1.78 sec in the 15-150 keV band
is 1.6 +- 0.4 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/598497/BA/