GCN Circular 32484

R. Caputo (GSFC), P. A. Evans (U Leicester), J.D. Gropp (PSU),
J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 11:55:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220826A (trigger=1121751).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 206.431, -44.044 which is 
   RA(J2000) = 13h 45m 44s
   Dec(J2000) = -44d 02' 39"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 20 sec.  The peak count rate
was ~3500 counts/sec (15-350 keV), at ~7 sec after the trigger. 

The XRT began observing the field at 11:56:42.9 UT, 81.2 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 206.41169, -44.03885 which
is equivalent to:
   RA(J2000)  = 13h 45m 38.81s
   Dec(J2000) = -44d 02' 19.9"
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This
location is 53 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 (9.05 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 2.8
(+2.60/-2.30) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 90 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  =	13:45:38.52 = 206.41049
  DEC(J2000) = -44:02:19.0  = -44.03862
with a 90%-confidence error radius of about 0.62 arc sec. This position is 3.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.89 with a 1-sigma error of about  0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.110. 

Burst Advocate for this burst is R. Caputo (regina.caputo AT nasa.gov). 
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/)