TITLE: GCN CIRCULAR NUMBER: 20349 SUBJECT: GRB 170101A: Swift detection of a burst DATE: 17/01/01 02:47:02 GMT FROM: Kim Page at U.of Leicester A. Y. Lien (GSFC/UMBC), D. Malesani (DARK/NBI and DTU Space), B. Mingo (U Leicester), K. L. Page (U Leicester) and T. N. Ukwatta (LANL) report on behalf of the Swift Team: At 02:26:01 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170101A (trigger=729293). The BAT on-board calculated location is RA, Dec 267.103, +11.654 which is RA(J2000) = 17h 48m 25s Dec(J2000) = +11d 39' 15" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 5 sec. The peak count rate was ~28000 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 23:58 UT on 2017 January 19. There will thus be no XRT or UVOT data for this trigger before this time. The Swift team wishes the astronomical community a happy 2017. Burst Advocate for this burst is A. Y. Lien (amy.y.lien 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.)