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 3830

GRB 050820: Swift detection of a GRB
2005-08-20T07:29:30Z (19 years ago)
David Burrows at PSU/Swift <>
M. Page (UCL-MSSL), D. Burrows (PSU), A. Beardmore (U. Leicester), D. 
Palmer (LANL),
J, Kennea (PSU), N. Gehrels (GSFC), C. Markwardt (GSFC/UMD), K. Page (U. 
T. Sakamoto (GSFC/NRC), M. Chester (PSU), P. Boyd (GSFC) report on behalf 
of the Swift team:

At 06:34:53 BAT triggered, located, and immediately slewed to GRB
050820 (trigger=151207).  The BAT on-board calculated position is
RA,Dec 337.400d, +19.578d {22h 29m 36s, 19d 34' 42"} (J2000) with an
uncertainty of 2 arcmin (radius, 90% containment, stat+sys).  The BAT
light curve shows a broad double-humped structure about 20 seconds
long, with peaks around T+1s and T+14 s, with a peak count rate
of ~1500 counts  per second (15-350 keV) at ~1 second after the trigger.

XRT began observing at 06:36:13 UT, 80s after the BAT trigger. A bright 
uncatalogued source was found in the field, which XRT was able to centroid 
on. The on-board calculated coordinates of this source are: 
RA(J2000):  22:29:37.8, Dec(J2000): 19:33:32.7, with an uncertainty of 7 
arcseconds radius (90% containment). This position lies 73 arcseconds from 
the center of the BAT error circle, and 6.2 arcseconds from the P60 
position (GCN 3829).

The UVOT began observations at 06:36:13 UT, 80s after the BAT trigger. 
There is no new source detected in the preliminary UVOT data in the XRT 
error circle.
Looking for U.S. government information and services? Visit