TITLE: GCN CIRCULAR NUMBER: 23670 SUBJECT: GRB 190110A: Swift detection of a burst DATE: 19/01/10 17:34:23 GMT FROM: Scott Barthelmy at NASA/GSFC B. Sbarufatti (PSU), S. D. Barthelmy (GSFC), J.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU), M. J. Moss (George Washington University), K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 17:24:48 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 190110A (trigger=883012). Swift did not slew due to an observing constraint. The BAT on-board calculated location is RA, Dec 276.882, -53.676, which is RA(J2000) = 18h 27m 32s Dec(J2000) = -53d 40' 34" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows several peaks with a total duration of about 15 sec. The peak count rate was ~7000 counts/sec (15-350 keV), at ~5 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 16:10 UT on 2019 February 01. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is B. Sbarufatti (bxs60 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.)