TITLE: GCN CIRCULAR NUMBER: 16870 SUBJECT: GRB 140930B Swift-BAT refined analysis DATE: 14/10/01 13:28:23 GMT FROM: Hans Krimm at NASA-GSFC W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), M. De Pasquale (INAF-IASFPA), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-61 to T+174 sec from the recent telemetry downlink, we report further analysis of BAT GRB 140930B (trigger #614094) (De Pasquale, et al., GCN Circ. 16857). The BAT ground-calculated position is RA, Dec = 6.360, 24.298 deg which is RA(J2000) = 00h 25m 26.4s Dec(J2000) = +24d 17' 53.3" with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 24%. The mask-weighted light curve shows a single FRED-like peak with structure, beginning at ~T-0.1 sec, peaking at T+0 sec and decaying to background by T+1.0 sec. There is no clear sign of extended emission. T90 (15-350 keV) is 0.84 +- 0.12 sec (estimated error including systematics). The time-averaged spectrum from T-0.10 to T+0.86 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.64 +- 0.19. The fluence in the 15-150 keV band is 4.2 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.12 sec in the 15-150 keV band is 4.0 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The position of GRB 140930B in the BAT hardness-duration diagram places it clearly in the short hard burst part of the diagram. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/614094/BA/