TITLE:   GCN CIRCULAR
NUMBER:  35345
SUBJECT: GRB 231215A: Swift-XRT observations
DATE:    23/12/15 11:15:35 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows
(PSU), J.A. Kennea (PSU), S. Campana (INAF-OAB) and G. Cusumano
(INAF-IASF PA) report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 231215A at 10:32:51.0 UT,
2725.7 seconds after the BAT trigger. Using promptly downlinked data we
find a bright, fading, uncatalogued X-ray source located at RA, Dec
9.74175, 57.64645 which is equivalent to:
   RA(J2000)  = 00h 38m 58.02s
   Dec(J2000) = +57d 38' 47.2"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 22 arcseconds from the BAT onboard position, within the BAT
error circle. 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 in excess of the Galactic value (4.25 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 4.7
(+2.34/-2.12) x 10^21 cm^-2 (90% confidence).