//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21420 SUBJECT: GRB 170807A: Swift detection of a burst DATE: 17/08/07 22:08:20 GMT FROM: David Palmer at LANL J.D. Gropp (PSU), S. D. Barthelmy (GSFC), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and A. Tohuvavohu (PSU) report on behalf of the Swift Team: At 21:56:09 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170807A (trigger=766821). Swift could not slew to the burst due to a Sun constraint. The BAT on-board calculated location is RA, Dec 143.379, -17.329 which is RA(J2000) = 09h 33m 31s Dec(J2000) = -17d 19' 44" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed two FRED structures with a total duration of about 40 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~1 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 06:56 UT on 2017 October 03. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is J.D. Gropp (jdg44 AT psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 21423 SUBJECT: GRB 170807A: Swift-BAT refined analysis DATE: 17/08/08 12:40:58 GMT FROM: Amy Lien at GSFC A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), J. D. Gropp (PSU), 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-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 170807A (trigger #766821) (Gropp et al., GCN Circ. 21420). The BAT ground-calculated position is RA, Dec = 143.434, -17.348 deg which is RA(J2000) = 09h 33m 44.2s Dec(J2000) = -17d 20' 51.9" with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 92%. The mask-weighted light curve shows a multi-peaked structure that starts at ~T0 and ends at ~T+50 s. The two main peaks occur at ~T+1 s and ~T+30 s, respectively. T90 (15-350 keV) is 48.5 +- 11.7 sec (estimated error including systematics). The time-averaged spectrum from T-0.42 to T+53.08 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.82 +- 0.15. The fluence in the 15-150 keV band is 8.6 +- 0.8 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.73 sec in the 15-150 keV band is 1.4 +- 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/766821/BA/