[vsnet-grb-info 21552] GRB 190109B: Swift-XRT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23651
SUBJECT: GRB 190109B: Swift-XRT observations
DATE:    19/01/09 13:21:11 GMT
FROM:    Phil Evans at U of Leicester  <pae9 at leicester.ac.uk>

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

The XRT began observing the field of GRB 190109B at 11:57:36.3 UT, 87.1
seconds after the BAT trigger. Using promptly downlinked data we find a
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
55.4870, 63.5920 which is equivalent to:
   RA(J2000)  = 03h 41m 56.88s
   Dec(J2000) = +63d 35' 31.2"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 180 arcseconds from the BAT onboard position, outside the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://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 4.56
x 10^21 cm^-2 (Willingale et al. 2013).