TITLE:   GCN CIRCULAR
NUMBER:  17426
SUBJECT: GRB 150206A: Swift-BAT refined analysis
DATE:    15/02/07 20:48:22 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), L. M. Z. Hagen (PSU), H. A. Krimm (GSFC/USRA),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC),
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 150206A (trigger #630019)
(Hagen, et al., GCN Circ. 17413).  The BAT ground-calculated position is
RA, Dec = 10.076, -63.181 deg, which is 
   RA(J2000)  =  00h 40m 18.1s 
   Dec(J2000) = -63d 10' 50.8" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 48%.
 
The mask-weighted light curve shows a slowly rising level starting at ~T-15 sec,
with two strong clusters of peaks at ~T+85 and ~T+98 sec, and returning
to baseline at ~T+230 sec.  T90 (15-350 keV) is 83.2 +- 7.8 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-22.3 to T+164.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.33 +- 0.04.  The fluence in the 15-150 keV band is 1.39 +- 0.03 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+98.82 sec in the 15-150 keV band
is 10.1 +- 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/630019/BA/