GCN Circular 26953

B. Sbarufatti (PSU), D. N. Burrows (PSU), J.D. Gropp (PSU),
J. A. Kennea (PSU), N. J. Klingler (PSU), S. Laha (GSFC/UMBC/CRESST),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), M. H. Siegel (PSU)
and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels
Swift Observatory Team:

At 22:41:15 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200131A (trigger=953689).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 3.095, +51.124 which is 
   RA(J2000) = 00h 12m 23s
   Dec(J2000) = +51d 07' 25"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 5 sec. There might be a small
pulse at T+30 s. The peak count rate was ~60000 counts/sec 
(15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 22:42:24.7 UT, 68.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 3.0942, 51.1158 which is equivalent to:
   RA(J2000)  = 00h 12m 22.61s
   Dec(J2000) = +51d 06' 56.9"
with an uncertainty of 4.9 arcseconds (radius, 90% containment). This
location is 29 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 3.76e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 77 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  =	00:12:22.57 =	3.09403
  DEC(J2000) = +51:07:00.4  =  51.11678
with a 90%-confidence error radius of about 0.61 arc sec. This position is 3.6
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.44 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.17. 

Burst Advocate for this burst is B. Sbarufatti (bxs60 AT psu.edu). 
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/)