NASA SWIFT: Swift/BAT detection of GRB 050716

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 3623
SUBJECT: Swift/BAT detection of GRB 050716
DATE: 05/07/16 13:34:23 GMT
FROM: Evert Rol at U.Leicester er45@star.le.ac.uk

E. Rol, C. Hurkett, K. Page (U. Leicester), S. Barthelmy, L. Barbier, A. Parsons (GSFC), J. Cummings (NRC, GSFC), D. Palmer (LANL), D. Burrows, J. Kennea (PSU), K. McGowan (MSSL), N. Gehrels (GSFC), report for the Swift team:

At 12:36:04 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 050716 (trigger=146227). The BAT on-board calculated location is RA,Dec 338.598d {+22h 34m 23s}, +38.696d {+38d 41′ 46″} (J2000), with an uncertainty of 4 arcmin (radius, including estimated systematic uncertainty; 90% containment). The BAT light curve showed a multi-peak structure with a duration of at least 40 seconds. The 15-350 keV peak count rate was ~1300 counts/sec, measured by BAT at ~10 seconds after the trigger.

The spacecraft slewed immediately and the XRT began observing the burst at 12:37:40 UT (96 seconds after the BAT trigger). The XRT found a bright, uncatalogued X-ray source. The on board calculated position is:

RA: 22h 34m 20.4s (J2000),
Dec: -38d 40′ 56.7″ (J2000).

This position is 60.6 arcseconds from the BAT position. The estimated uncertainty is 6 arcseconds radius (90% containment).

The Swift Ultra Violet/Optical Telescope (UVOT) observations began at 12:37:43 UT, 99 seconds after the BAT trigger. The first data taken after the spacecraft settled was a 100 sec exposure using the V filter with the midpoint of the observation at 149 sec after the BAT trigger. Based on comparisons to the DSS, we detect no new source at the XRT position.