GRB 051001: Swift Detection of a Burst

TITLE: GCN GRB OBSERVATION REPORT
NUMBER: 4051
SUBJECT: GRB 051001: Swift Detection of a Burst
DATE: 05/10/01 11:55:29 GMT
FROM: Hans Krimm at NASA-GSFC krimm@milkyway.gsfc.nasa.gov

A. Moretti (OAB), J. Cummings (GSFC-NRC), N. Gehrels (GSFC), S. Hunsberger (PSU), H. Krimm (GSFC-USRA), C. Markwardt (GSFC-UMD), F. Marshall (GSFC), D. Palmer (LANL), P. Romano (OAB), on behalf of the Swift team:

GRB 051001: Swift Detection of a Burst

At 11:11:36 UT, Swift-BAT triggered and located GRB051001 (trigger=157870). The spacecraft slewed immediately, which in this case was 75 seconds after the image trigger. The BAT on-board calculated location is RA,Dec 350.973d, -31.528d {23h 23m 53s, -31d 31′ 39″} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). Since this was an image trigger there is no obvious information in the light curve.

XRT began observing the field at 11:14:42, 185 seconds after the BAT trigger. Onboard centroiding found a bright fading uncatalogued X-ray source in the field of view at the following coordinates:

RA(J2000): 23h 23m 49.1
Dec(J2000): -31d 31′ 15.6″

We estimate the uncertainty of this position to be 6 arcseconds (radius, 90% containment). This position is 61 arcseconds from the BAT position above.

UVOT began observing the field 189 seconds after the trigger. The small image does not overlap the XRT error circle. No new source was seen in the list of sources from the entire UVOT field of view.

We are currently in the portion of the orbits where the spacecraft does not pass over the Malindi downlink station. Therefore, it will be at least four hours before we have access to the full data set for the refined analyses.