[vsnet-grb-info 25678] GRB 200522A: Swift detection of a short burst

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27778
SUBJECT: GRB 200522A: Swift detection of a short burst
DATE:    20/05/22 12:02:37 GMT
FROM:    Kim Page at U.of Leicester  <klp5 at leicester.ac.uk>

P. A. Evans (U Leicester), J.D. Gropp (PSU),
S. Laha (GSFC/UMBC/CRESST), A. Y. Lien (GSFC/UMBC) and
K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 11:41:34 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200522A (trigger=973628).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 5.667, -0.282 which is 
   RA(J2000) = 00h 22m 40s
   Dec(J2000) = -00d 16' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 1 sec.  The peak count rate
was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 11:42:57.5 UT, 83.4 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 5.6823, -0.2824 which
is equivalent to:
   RA(J2000)  = 00h 22m 43.76s
   Dec(J2000) = -00d 16' 56.7"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 55 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at https://www.swift.ac.uk/sper.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data does not constrain the column density. 

No UVOT analysis is available at this time. 

Burst Advocate for this burst is P. A. Evans (pae9 AT star.le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)