NASA Swift: GRB 060522: Swift detection of a burst with possible optical afterglow

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 5150
SUBJECT: GRB 060522: Swift detection of a burst with possible optical afterglow
DATE: 06/05/22 02:47:17 GMT
FROM: Derek Fox at PSU dfox@astro.psu.edu

D. B. Fox (PSU), J. R. Cummings (NASA/ORAU), N. Gehrels (NASA/GSFC), S. T. Holland (GSFC/USRA), S. D. Hunsberger (PSU), J. A. Kennea (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), F. E. Marshall (NASA/GSFC), D. C. Morris (PSU), D. M. Palmer (LANL) and M. Stamatikos (NASA/GSFC/ORAU) report on behalf of the Swift Team:

At 02:11:18 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 060522 (trigger=211117). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 322.951, +2.876 {21h 31m 48s, +02d 52′ 33″} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Since this was a 64-sec BAT image trigger, there is not enough information in the light curve at this time to describe the time profile of the burst. The peak count rate was ~500 counts/sec (15-350 keV), at ~5 sec after the trigger.

The XRT began taking data at 02:13:40 UT, 142 seconds after the BAT trigger. The XRT on-board centroid algorithm did not find a source in the image, however analysis of initial downlinked data shows the presence of an uncatalogued point source at the following coordinates: RA (J2000) = 21:31:44.9, Dec(J2000) = +02:53:08.5, with an error radius of 4.0 arcseconds (90% containment). This source is 61 arcseconds from the BAT position.

The UVOT began a 100 s white exposure at 02:13:47. A point source is detected in the XRT error circle with a white magnitude of 19.7. This source is not present in the DSS. The coordinates of this source are 21:31:44.8, +02:53:10 (J2000) with an uncertainty of +/- 0.6 arcsec (90% containment).