TITLE:   GCN CIRCULAR
NUMBER:  28800
SUBJECT: GRB 201026A: Swift-BAT refined analysis
DATE:    20/10/29 01:11:22 GMT
FROM:    Sibasish Laha at GSFC  <sibasish.laha@nasa.gov>

GRB 201026A: Swift-BAT refined analysis

S. D. Barthelmy (GSFC), S. B. Cenko (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),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-60 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 201026A (trigger #1002103)
(S. B. Cenko et al., GCN Circ. 28784).  The BAT ground-calculated position is
RA, Dec = 196.696, 83.807 deg which is
   RA(J2000)  =  13h 06m 47.0s
   Dec(J2000) = +83d 48' 24.3"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 46%.

The BAT light curve showed a complex structure. There are two prominent peaks, at
~ T+0 sec and T+210 sec with a duration of about 50 sec and 60 sec respectively.
There is a small peak at T+140 to T+170 sec, and possibly a precursor at
T-60 to T-40 sec.
T90 (15-350 keV) is 135.38 +- 120.84 sec (estimated error including systematics).

The time-averaged spectrum from T-13 to T+146 sec and T+165 to T+230 sec is best fit by
a simple power-law model.  The power law index of the time-averaged spectrum is
1.94 +- 0.09.  The fluence in the 15-150 keV band is 5.6 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+1.05 sec in the 15-150 keV band
is 2.2 +- 0.3 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/1002103/BA/