TITLE:   GCN CIRCULAR
NUMBER:  28682
SUBJECT: GRB 201017A: Swift-BAT refined analysis
DATE:    20/10/18 22:26:32 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),  A. D'Ai (INAF-IASFPA),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+823 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 201017A (trigger #1000613)
D'Ai, et al., GCN Circ. 28666).  The BAT ground-calculated position is
RA, Dec = 36.587, 66.663 deg which is 
  RA(J2000)  =  02h 26m 20.9s 
  Dec(J2000) = +66d 39' 45.7" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 37%.

The mask-weighted light curve shows a single, symmetrical main peak from roughly
T-5 sec to T+5 sec, peaking at T+1 sec, followed by weaker emission out to T+20 sec.
T90 (15-350 keV) is 22.08 +- 6.25 sec (estimated error including systematics).

The time-averaged spectrum from T-2.77 to T+23.87 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.48 +- 0.25.  The fluence in the 15-150 keV band is 9.0 +- 1.4 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+0.87 sec in the 15-150 keV band
is 1.8 +- 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/1000613/BA/