Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 5055

GRB 060502B: Swift detection of a short burst
2006-05-02T18:08:11Z (18 years ago)
Scott Barthelmy at NASA/GSFC <>
E. Troja (INAF-IASFPA), S. D. Barthelmy (GSFC),
P. T. Boyd (NASA/GSFC), D. N. Burrows (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),
V. La Parola (INAF-IASFPA), V. Mangano (INAF-IASFPA),
F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester),
K. L. Page (U Leicester), D. M. Palmer (LANL),
T. Sakamoto (NASA/ORAU), G. Tagliaferri (INAF-OAB) and
D. E. Vanden Berk (PSU) report on behalf of the Swift Team:

At 17:24:41 UT, the Swift Burst Alert Telescope (BAT) triggered and
located the short GRB 060502B (trigger=208275).  Swift slewed immediately
to the burst.  The BAT on-board calculated location is 
RA,Dec 278.936, +52.632 {18h 35m 45s, +52d 37' 56"} (J2000)
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The TDRSS BAT light curve shows a single spike
with a FWHM of less than 128 msec.  The peak count rate
was ~10000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began taking data at 17:25:51 UT, 70 seconds after the BAT
trigger. The XRT on-board centroid algorithm did not find a source in
the image, however analysis of downlinked data reveals a faint point
source at the following coordinates: RA(J2000) = 18h 35m 45.9s,
Dec(J2000) = 52d 37m 38.1s, with an estimated uncertainty of 10
arcseconds radius (90% containment). This position is 20 arcseconds
from BAT localization. We note that the XRT position lies 2.5
arcseconds from an possible galaxy with R=18.5 in the APM-North
catalogue (McMahon et al., 2000). 

UVOT took a finding chart exposure of 100 seconds with the White 
(160-650 nm) filter starting 74.2 seconds after the BAT trigger. 
There is no detected new source in the rapidly available 2.7'x2.7' 
sub-image, to a limiting White magnitude of about 19.1. 

We are currently in the beginning of the Malindi downlink gap, so we
will not have the full data set until at least 01:00 03/May/06 UT.
Looking for U.S. government information and services? Visit