TITLE: GCN CIRCULAR NUMBER: 8044 SUBJECT: GRB 080727C, Swift-BAT refined analysis DATE: 08/07/28 20:46:16 GMT FROM: Scott Barthelmy at NASA/GSFC E. Fenimore (LANL), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+843 sec from recent telemetry downlinks, we report further analysis of BAT GRB 080727C (trigger #318170) (Parsons, et al., GCN Circ. 8035). The BAT ground-calculated position is RA, Dec = 32.638, 64.130 deg which is RA(J2000) = 02h 10m 33.2s Dec(J2000) = +64d 07' 48.6" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 77%. The mask-weighted light curve shows several overlapping peaks starting at ~T-5 sec and ending at ~T+200 sec. T90 (15-350 keV) is 79.7 +- 8.8 sec (estimated error including systematics). The time-averaged spectrum from T-3.3 to T+116.3 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.87 +- 0.20, and Epeak of 143.2 +- 50.0 keV (chi squared 66 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 5.2 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+15.23 sec in the 15-150 keV band is 2.3 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.30 +- 0.05 (chi squared 81 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/318170/BA/