TITLE:   GCN CIRCULAR
NUMBER:  28350
SUBJECT: GRB 200903A: Swift detection of a burst
DATE:    20/09/03 01:06:11 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

A. P. Beardmore (U Leicester), J.D. Gropp (PSU),
A. Y. Lien (GSFC/UMBC), M. J. Moss (GWU), K. L. Page (U Leicester) and
D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 00:44:22 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200903A (trigger=994389).  Swift did not slew immediately 
due to an observing constraint. 
The BAT on-board calculated location is 
RA, Dec 164.311, +50.501 which is 
   RA(J2000) = 10h 57m 15s
   Dec(J2000) = +50d 30' 02"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 30 sec. The peak count rate
was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to a Sun observing constraint, Swift cannot slew to the BAT
position until 14:33 UT on 2020 September 12. There will thus be no XRT
or UVOT data for this trigger before this time. 

Burst Advocate for this burst is A. P. Beardmore (apb 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/)