TITLE:   GCN CIRCULAR
NUMBER:  17401
SUBJECT: GRB 150202A, Swift-BAT refined analysis
DATE:    15/02/04 14:19:35 GMT
FROM:    Hans Krimm at NASA-GSFC  <hans.a.krimm@nasa.gov>

T. Sakamoto (AGU), 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 (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 150202A (trigger #629547)
(Krimm, et al., GCN Circ. 17376).  The BAT ground-calculated position is
RA, Dec = 39.261, -33.132 deg which is
    RA(J2000)  =  02h 37m 02.6s
    Dec(J2000) = -33d 07' 56.1"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.

The mask-weighted light curve shows a complex structure with multiple peaks. The 
first emission episode runs from T-2 to T+10 sec and then second episode from 
T+12 to ~T+30 sec. T90 (15-350 keV) is 25.7 +- 4.3 sec (estimated error 
including systematics).

The time-averaged spectrum from T-1.7 to T+27.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.50 +- 0.19.  The fluence in the 15-150 keV band is 6.1 +- 0.7 x 10^-7 erg/cm2. 
The 1-sec peak photon flux measured from T+17.40 sec in the 15-150 keV band is 
1.0 +- 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/629547/BA/