TITLE:   GCN CIRCULAR
NUMBER:  29534
SUBJECT: GRB 210217A: Swift-BAT refined analysis
DATE:    21/02/18 18:01:32 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
K. K. Simpson (PSU), 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 210217A (trigger #1033264)
(Simpson et al., GCN Circ. 29521).  The BAT ground-calculated position is
RA, Dec = 97.578, 68.715 deg which is
   RA(J2000)  =  06h 30m 18.6s
   Dec(J2000) = +68d 42' 55.4"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 30%.

The mask-weighted light curve shows a single-peaked FRED-like structure
that starts and peaks at ~T0, and ends at ~T+5 s. T90 (15-350 keV) is
4.22 +- 1.15 sec (estimated error including systematics).

The time-averaged spectrum from T-0.65 to T+4.89 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 2.01 +- 0.16.  The fluence in the 15-150 keV band
is 6.8 +- 0.7 x 10^-7 erg/cm2. The 1-sec peak photon flux measured
from T-0.13 sec in the 15-150 keV band is 5.1 +- 0.5 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/1033264/BA/