TITLE: GCN CIRCULAR NUMBER: 35863 SUBJECT: Swift Trigger 1218645: Another detection of Swift J151857.0-572147 DATE: 24/03/04 18:39:12 GMT FROM: Jamie Kennea at Penn State E. Ambrosi (INAF-IASFPA), J. A. Kennea (PSU), A. Y. Lien (U Tampa), M. J. Moss (GSFC), K. L. Page (U Leicester), M. H. Siegel (PSU) and M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 18:26:54 UT, the Swift Burst Alert Telescope (BAT) triggered and located Swift J151857.0-572147 (trigger=1218645). Swift slewed immediately to the source. The BAT on-board calculated location is RA, Dec 229.720, -57.363 which is RA(J2000) = 15h 18m 53s Dec(J2000) = -57d 21' 47" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). This is the third BAT trigger on Swift J151857.0-572147 (GCN #35849, GCN #35853, GCN #35858). Repeated triggers indicate that the source is continuing to brighten.