TITLE:   GCN CIRCULAR
NUMBER:  28755
SUBJECT: GRB 201021C: Swift-BAT refined analysis
DATE:    20/10/22 22:30:34 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 201021C (trigger #1001130)
(Lien, et al., GCN Circ. 28730).  The BAT ground-calculated position is
RA, Dec = 12.503, -55.862 deg which is 
   RA(J2000)  =  00h 50m 00.6s 
   Dec(J2000) = -55d 51' 44.0" 
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 80%.

The mask-weighted light curve shows a single peak running from ~T-5 sec to 
T+20 sec, with a broad peak around T+3 sec. T90 (15-350 keV) is 24.38 +- 6.76 sec 
(estimated error including systematics).

The time-averaged spectrum from T-4.19 to T+27.95 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.63 +- 0.15.  The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-3.62 sec in the 15-150 keV band
is 1.0 +- 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/1001130/BA/