TITLE:   GCN CIRCULAR
NUMBER:  38367
SUBJECT: GRB 241128A: Swift detection of a burst
DATE:    24/11/28 16:37:44 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>

R. Brivio (INAF-OAB), M. Ferro (INAF-OAB), C. Gronwall (PSU),
R. Gupta (NASA GSFC), A. Y. Lien (U Tampa), K. L. Page (U Leicester),
D. M. Palmer (LANL), C. Salvaggio (INAF-OAB) and
T. Sbarrato (INAF-OAB) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 16:14:34 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 241128A (trigger=1270999).  Swift slewed immediately to the burst.
The BAT on-board calculated location is 
RA, Dec 273.724, +33.435 which is 
  RA(J2000) = 18h 14m 54s
  Dec(J2000) = +33d 26' 07"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  Although a telemetry gap prevented
the download of a BAT lightcurve, the trigger duration of 4 s
indicates that this is a long burst.

The XRT began observing the field at 16:16:32.2 UT, 118.0 seconds after
the BAT trigger. No source was detected in the 2.5-s promptly available
image. We are waiting for the full dataset to detect and localise the
XRT counterpart.

There are no prompt UVOT data available at this time.

Although this source has not been confirmed during the short XRT observation
(truncated by entrance into the SAA) or by the non-availability of the
BAT lightcurve, the strength of peak (8.4 sigma) in the BAT image
indicates that this is an astrophysical source.

Burst Advocate for this burst is R. Brivio (riccardo.brivio AT inaf.it).
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/)