TITLE:   GCN CIRCULAR
NUMBER:  39606
SUBJECT: GRB 250306A: Swift detection of a burst
DATE:    25/03/06 16:51:42 GMT
FROM:    David Palmer at LANL <palmer@lanl.gov>

P. A. Evans (U Leicester), R. Gupta (NASA GSFC), J. A. Kennea (PSU),
K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 16:30:08 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 250306A (trigger=1293340).  Swift did not slew to the burst.
The BAT on-board calculated location is 
RA, Dec 354.730, -47.993 which is 
   RA(J2000) = 23h 38m 55s
   Dec(J2000) = -47d 59' 35"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 10 sec.  The peak count rate
was ~14,000 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 01:23 UT on 2025 March 18. There will thus be no XRT or
UVOT data for this trigger before this time.

Burst Advocate for this burst is P. A. Evans (pae9 AT leicester.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/)