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GCN Circular 17687

Subject

Swift trigger 637807 is probably not an astrophysical source

Date

2015-04-12T08:57:02Z (10 years ago)

From

Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>

D. Malesani (DARK/NBI) and K. L. Page (U Leicester) report on behalf
of the Swift Team:

At 08:32:10 UT, the Swift Burst Alert Telescope (BAT) imaged a peak
with a projected location near XTE J1814-338 (trigger=637807). 
Due to a visibility constraint, Swift did not slew immediately to
the location. The BAT on-board calculated location is
RA, Dec = 273.356, -33.940, which is 
  RA(J2000)  =  18h 13m 25s 
  Dec(J2000) = -33d 56' 124"
with an uncertainty of 4 arcmin (radius, 90% containment, including
systematic uncertainty).  As is usual for image triggers, there is
no significant variation in the immediately available BAT lightcurve. 

Given the very low significance of the trigger (5.87 sigma), and that
the BAT position is more than 10 arcmin away from the known position
of XTE J1814-338, we do not believe that the trigger is associated
with XTE J1814-338 and it is unlikely to have been caused by a real
astrophysical source.