TITLE: GCN CIRCULAR NUMBER: 23420 SUBJECT: GRB 181110A, Swift-BAT refined analysis DATE: 18/11/11 01:33:53 GMT FROM: Amy Lien at GSFC A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), P. A. Evans (U Leicester), H. A. Krimm (NSF/USRA), 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-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 181110A (trigger #871316) (Evans et al., GCN Circ. 23413). The BAT ground-calculated position is RA, Dec = 302.330, -36.878 deg which is RA(J2000) = 20h 09m 19.2s Dec(J2000) = -36d 52' 41.4" with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a multi-peaked structure that starts at ~T-110 s and ends at ~T+130 s. The main peak occurs at ~T+25 s. T90 (15-350 keV) is 138.4 +- 10.9 sec (estimated error including systematics). The time-averaged spectrum from T-109.3 to T+129.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.02 +- 0.05. The fluence in the 15-150 keV band is 9.9 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+25.03 sec in the 15-150 keV band is 3.7 +- 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/871316/BA/