TITLE:   GCN CIRCULAR
NUMBER:  29435
SUBJECT: GRB 210207B: Swift-BAT refined analysis
DATE:    21/02/09 01:29:50 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

H. A. Krimm (NSF), S. D. Barthelmy (GSFC),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (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 210207B (trigger #1031297)
(Lien et al., GCN Circ. 29420).  The BAT ground-calculated position is
RA, Dec = 270.614, 53.700 deg which is
   RA(J2000)  =  18h 02m 27.3s
   Dec(J2000) = +53d 42' 01.1"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 56%.

The mask-weighted light curve shows a multi-peaked structure that
starts at ~T0 and ends at ~T+106 s. The main peak occurs at ~T+43 s.
T90 (15-350 keV) is 95.69 +- 4.52 sec (estimated error including
systematics).

The time-averaged spectrum from T-0.25 to T+106.40 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
1.20 +- 0.07.  The fluence in the 15-150 keV band is 4.3 +- 0.2 x 10^-6
erg/cm2.
The 1-sec peak photon flux measured from T+43.16 sec in the 15-150 keV band
is 3.1 +- 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/1031297/BA/