TITLE: GCN CIRCULAR NUMBER: 31828 SUBJECT: GRB 220404A: Swift detection of a burst DATE: 22/04/04 12:07:35 GMT FROM: Kim Page at U.of Leicester S. B. Cenko (GSFC), V. D'Elia (SSDC & INAF-OAR), S. Dichiara (PSU), J.D. Gropp (PSU), K. L. Page (U Leicester) and T. M. Parsotan (GSFC/UMBC/CRESSTII) report on behalf of the Neil Gehrels Swift Observatory Team: At 11:54:30 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 220404A (trigger=1101133). The BAT on-board calculated location is RA, Dec 50.448, +10.005 which is RA(J2000) = 03h 21m 47s Dec(J2000) = +10d 00' 16" 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 10 sec. The peak count rate was ~1200 counts/sec (15-350 keV), at ~2 sec after the trigger. Due to a Sun observing constraint, Swift cannot slew to the BAT position until 20:40 UT on 2022 June 28. There will thus be no XRT or UVOT data for this trigger before this time. Burst Advocate for this burst is S. B. Cenko (brad.cenko 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/)