TITLE: GCN CIRCULAR NUMBER: 8709 SUBJECT: GRB 081222, Swift-BAT refined analysis DATE: 08/12/22 19:28:59 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift E. E. Fenimore (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), D. Grupe (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-119 to T+183 sec from the recent telemetry downlink, we report further analysis of BAT GRB 081222 (trigger #337914) (Grupe, et al., GCN Circ. 8691). The BAT ground-calculated position is RA, Dec = 22.748, -34.095 deg which is RA(J2000) = 01h 30m 59.5s Dec(J2000) = -34d 05' 41.4" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The burst was in the fully-coded field of view. The mask-weighted light curve shows a main peak with several subpeaks from about T+0 to T+20 sec and an exponential tail visible to about T+70 sec. T90 (15-350 keV) is 24 +- 3 sec (estimated error including systematics). The time-averaged spectrum from T-0.6 to T+38.0 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.08 +- 0.15, and Epeak of 131 +- 31 keV (chi squared 45.61 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 4.8 +- 0.1 x 10^-06 erg/cm2 and the 1-sec peak flux measured from T+3.45 sec in the 15-150 keV band is 7.7 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.48 +- 0.03 (chi squared 68.25 for 57 d.o.f.). 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/337914/BA/