TITLE:   GCN CIRCULAR
NUMBER:  23321
SUBJECT: GRB 181010A: Swift-BAT refined analysis
DATE:    18/10/10 21:12:55 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@milkyway.gsfc.nasa.gov>

A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
H. A. Krimm (NSF/USRA), C. B. Markwardt (GSFC), A. Melandri (INAF-OAB),
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-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 181010A (trigger #866434)
(Melandri, et al., GCN Circ. 23309).  The BAT ground-calculated position is
RA, Dec = 52.574, -23.023 deg, which is 
   RA(J2000)  =  03h 30m 17.7s 
   Dec(J2000) = -23d 01' 22.7" 
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 85%.
 
The mask-weighted light curve shows several overlapping peaks starting
at ~T-5sec, peaking at ~T+8 sec, and returning to baseline at ~T+15 sec.
T90 (15-350 keV) is 16.4 +- 2.2 sec (estimated error including systematics).
 
The time-averaged spectrum from T-4.04 to T+15.21 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.52 +- 0.15.  The fluence in the 15-150 keV band is 6.9 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+7.43 sec in the 15-150 keV band
is 1.4 +- 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/866434/BA/