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GCN Circular 35448

GRB 240101A: Swift detection of a burst
2024-01-01T14:45:57Z (4 months ago)
K.L. Page at U Leicester <>

S. B. Cenko (GSFC), C. Gronwall (PSU), J.D. Gropp (PSU) and
K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift
Observatory Team:

The Swift Burst Alert Telescope (BAT) triggered and located GRB 240101A
(trigger=1205708), and Swift has slewed to this burst. The trigger time is
believed to be no earlier than 12:52 UT. Given the loss of some of the TDRSS
notices, we will not have values for T0 or the BAT Position until the
full data have been downloaded, in approximately 1.25 hours (by around 16:05

Using promptly downlinked data we find an uncatalogued X-ray source
with an enhanced position: RA, Dec 10.34819, 8.51706 which is
equivalent to:
   RA(J2000)  = 00h 41m 23.57s
   Dec(J2000) = +08d 31' 01.4"
with an uncertainty of 1.9 arcseconds (radius, 90% containment). This
position may be improved as more data are received; the latest position
is available at 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (5.84 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 1.1
(+0.67/-0.52) x 10^22 cm^-2 (90% confidence). 

No afterglow is detected in the initial UVOT data products. 

Burst Advocate for this burst is S. B. Cenko (brad.cenko AT 
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:

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