//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20583 SUBJECT: GRB 170203A: Swift detection of a burst DATE: 17/02/03 00:13:29 GMT FROM: David Palmer at LANL J. L. Racusin (NASA/GSFC), A. Cholden-Brown (PSU), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 00:03:41 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170203A (trigger=736432). Swift could not slew to the burst due to the Sun observing constraint. The BAT on-board calculated location is RA, Dec 332.860, +25.173 which is RA(J2000) = 22h 11m 26s Dec(J2000) = +25d 10' 24" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 40 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~4 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 01:25 UT on 2017 April 10. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is J. L. Racusin (judith.racusin AT nasa.gov). 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: 20597 SUBJECT: GRB 170203A: Swift-BAT refined analysis DATE: 17/02/03 17:29:04 GMT FROM: Hans Krimm at NSF/NASA-GSFC J. R. Cummings (CPI), S. D. Barthelmy (GSFC), N. Gehrels (GSFC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), J. L. Racusin (NASA/GSFC), 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 170203A (trigger #736432) (Racusin, et al., GCN Circ. 20583). The BAT ground-calculated position is RA, Dec = 332.861, 25.186 deg which is RA(J2000) = 22h 11m 26.6s Dec(J2000) = +25d 11' 08.4" with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 67%. The mask-weighted light curve shows a single main peak, which starts at T+0 sec, peaks at T+5 sec and decays to background by T+30 sec. There is a much weaker peak from T+25 to T+50 sec. T90 (15-350 keV) is 45.2 +- 6.4 sec (estimated error including systematics). The time-averaged spectrum from T-0.04 to T+48.43 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.53 +- 0.29. The fluence in the 15-150 keV band is 6.2 +- 1.1 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+3.70 sec in the 15-150 keV band is 0.8 +- 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/736432/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20667 SUBJECT: GRB 170203A: 15 GHz upper limits from AMI DATE: 17/02/12 19:22:31 GMT FROM: Kunal Mooley at Oxford U K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester) The AMI Large Array robotically triggered on the Swift alert for GRB 170203A (Racusin et al., GCN 20583) as part of the 4pisky program, and subsequent follow up observations were obtained up to 10 days post-burst. Our observations at 15 GHz on 2016 Feb 03.37, Feb 04.56, Feb 06.56 and Feb 10.55 (UT) do not reveal any radio source at the BAT location (Cummings et al., GCN 20597), with 3sigma upper limits of 183 uJy, 84 uJy, 75 uJy and 171 uJy respectively. We thank the AMI staff for scheduling these observations. The AMI-GRB database is a log of all GRB follow up observations with the AMI, and is available at http://4pisky.org/ami-grb/.