GCN Circular 41985
Subject
GRB 250925A: Swift detection of a burst
Event
Date
2025-09-25T17:19:22Z (7 days ago)
From
David Palmer at LANL <palmer@lanl.gov>
Via
email
S. Dichiara (PSU), R. Gupta (NASA GSFC),
N. J. Klingler (GSFC/UMBC/CRESSTII), S. Lanava (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Neil Gehrels Swift Observatory Team:
At 17:04:26 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 250925A (trigger=1352124). Swift could not immediately
slew to the burst due to an observing constraint.
The BAT on-board calculated location is
RA, Dec 341.201, +46.574 which is
RA(J2000) = 22h 44m 48s
Dec(J2000) = +46d 34' 25"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve is only available until
T+8s, but this shows a complex peak of at least 20 s duration.
The peak count rate was ~1400 counts/sec (15-350 keV), at ~1 sec
after the trigger.
Due to an observing constraint, Swift will not slew at this time. XRT and UVOT
data will be obtained later.
Burst Advocate for this burst is S. Dichiara (sbd5667 AT psu.edu).
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/)