[vsnet-grb-info 26961] GRB 201216C: Swift-XRT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29064
SUBJECT: GRB 201216C: Swift-XRT observations
DATE:    20/12/17 00:58:40 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at leicester.ac.uk>

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

The XRT began observing the field of GRB 201216C at 23:56:58.5 UT,
2966.8 seconds after the BAT trigger. Using promptly downlinked data we
find a fading, uncatalogued X-ray source located at RA, Dec 16.37114,
16.51659 which is equivalent to:
   RA(J2000)  = 01h 05m 29.07s
   Dec(J2000) = +16d 30' 59.7"
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This
location is 86 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 (5.04 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 7.4
(+2.86/-2.53) x 10^21 cm^-2 (90% confidence).