Swift trigger 143708 is really GRB 050701

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 3556
SUBJECT: Swift trigger 143708 is really GRB 050701
DATE: 05/07/01 12:38:19 GMT
FROM: Hans Krimm at NASA-GSFC krimm@milkyway.gsfc.nasa.gov

P. Boyd (GSFC/UMBC), L. Barbier (NASA GSFC), D. Burrows (PSU), N. Gehrels (NASA GSFC), M. Goad (Leicester), C. Hurkett (Leicester), M. Ivanushkina (PSU), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. Page (Leicester U), D. Palmer (LANL), A. Parsons (NASA GSFC), T. Poole (MSSL), P. Roming (PSU)

At 11:42:59 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB050701(trigger=143708). The BAT on-board calculated location is RA,Dec 227.287d -59.419d {+15h 09m 09s, -59d 25′ 06″} (J2000) with an uncertainty of 3 arcmin (radius, 3-sigma, including estimated systematic uncertainty). The detection significance in the image plane is 14.2 sigma. The BAT light curve showed a complex multipeaked structure with a duration of about 40 seconds. The peak count rate of 5000 counts/sec (15-350 keV) was measured by BAT in the 1-sec time interval centered on T+15 sec after the trigger.

Because this burst was 40 arcminutes from a known source (PSR 1509-58) it was incorrectly classified on-board and so Swift did not automatically slew to observe this burst. A target of opportunity observation is being planned.