TITLE: GCN CIRCULAR NUMBER: 22720 SUBJECT: GRB 180512A: Swift-BAT refined analysis DATE: 18/05/13 16:56:18 GMT FROM: Amy Lien at GSFC J. R. Cummings (CPI), S. D. Barthelmy (GSFC), A. Deich (PSU), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), 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 180512A (trigger #832119) (Deich et al., GCN Circ. 22710). The BAT ground-calculated position is RA, Dec = 201.940, 21.404 deg which is RA(J2000) = 13h 27m 45.5s Dec(J2000) = +21d 24' 15.7" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 67%. The mask-weighted light curve shows a weak pulse that starts at ~T+30 s, peaks at ~T+40 s, and ends at ~T+55 s. The short spike at T+54.4 s is due to detector noise. T90 (15-350 keV) is 24.0 +- 7.1 sec (estimated error including systematics). Note that the burst went out of the BAT FOV at T+469 s. The large pulse seen in the BAT raw light curve from ~T+400 s to ~T+550 s was from a bright background source that came in and out of the BAT FOV during this time interval. The time-averaged spectrum from T+29.00 to T+55.00 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.10 +- 0.27. The fluence in the 15-150 keV band is 4.2 +- 0.7 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+39.00 sec in the 15-150 keV band is 0.6 +- 0.2 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/832119/BA/