TITLE: GCN CIRCULAR NUMBER: 20968 SUBJECT: GRB 170330A: Swift-BAT refined analysis DATE: 17/04/01 06:16:03 GMT FROM: Amy Lien at GSFC A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), P. D'Avanzo (INAF-OAB), N. Gehrels (GSFC), 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 170330A (trigger #744773) (D'Avanzo et al., GCN Circ. 20944). The BAT ground-calculated position is RA, Dec = 283.331, -13.458 deg which is RA(J2000) = 18h 53m 19.4s Dec(J2000) = -13d 27' 29.2" with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 46%. The mask-weighted light curve shows a multi-peaked structure that lasts until ~T+126 s, with the main peak occurs around ~T-135 s. The burst came into the BAT field of view at ~T-170 s during a pre-planned spacecraft slew. Therefore, the burst emission might have started before ~T-170 s. T90 (15-350 keV) is 144.73 +- 3.51 sec (estimated error including systematics). The time-averaged spectrum from T-143.2 to T+126.2 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.38 +- 0.09. The fluence in the 15-150 keV band is 5.6 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-134.71 sec in the 15-150 keV band is 4.5 +- 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/744773/BA/