GRB 210618A: Swift detection of a burst

At 01:43:37 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 210618A (trigger=1056426). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 235.820, +46.043 which is RA(J2000) = 15h 43m 17s Dec(J2000) = +46d 02' 36" 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 3 sec. The peak count rate was ~3600 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 01:44:42.2 UT, 65.3 seconds after the BAT trigger. No source was detected in the 2.5-s promptly available image. Due to a short visibility interval, no further data were immediately collected. We are waiting for the full dataset to detect and localise the XRT counterpart. Due to the short visibility window, UVOT data are not available at this time. Burst Advocate for this burst is M. G. Bernardini (grazia.bernardini AT brera.inaf.it). 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/)