GCN Circular 22477
P. D'Avanzo (INAF-OAB), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), A. Melandri (INAF-OAB), K. L. Page (U Leicester) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 17:48:54 UT, the Swift Burst Alert Telescope (BAT) triggered and located MAXI J1820+070 (trigger=814090). Swift did not slew to the source because Swift was already looking at this source. The BAT on-board calculated location is RA, Dec 275.091, +7.188, which is RA(J2000) = 18h 20m 22s Dec(J2000) = +07d 11' 17" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a few peaks with a duration of about 30 sec. The peak count rate was ~1100 counts/sec (15-350 keV), at ~2 sec after the trigger. Swift was observing MAXI J1820+070 when BAT triggered, at a higher merit than the BAT trigger. As such no prompt XRT or UVOT data are available for this trigger.