TITLE:   GCN CIRCULAR
NUMBER:  35461
SUBJECT: GRB 240102A: Swift detection of a burst
DATE:    24/01/02 18:19:27 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>


J.D. Gropp (PSU), S. Dichiara (PSU), J. A. Kennea (PSU),
K. L. Page (U Leicester) and M. A. Williams (PSU) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 17:34:55 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 240102A (trigger=1205899). Swift slewed immediately to the 
burst. The BAT on-board calculated location is 
RA, Dec 96.846, -20.024 which is 
   RA(J2000) = 06h 27m 23.0s
   Dec(J2000) = -20d 01' 26.4"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty). We currently have no information regarding the
BAT light-curve. 

The XRT began observing the field at 17:37:00.6 UT, 125 seconds
after the BAT trigger. Using promptly downlinked data we find an
uncatalogued X-ray source with an enhanced position: RA, Dec 96.83800,
-20.04076 which is equivalent to:
   RA(J2000)  = 06h 27m 21.12s
   Dec(J2000) = -20d 02' 26.7"
with an uncertainty of 1.9 arcseconds (radius, 90% containment). This 
position is 66 arc-seconds from the BAT localization. This
position may be improved as more data are received; the latest position
is available at https://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 2.34
x 10^21 cm^-2 (Willingale et al. 2013). 

No afterglow is detected in the initial UVOT data products. 

Burst Advocate for this burst is J.D. Gropp (jdg44 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/)