TITLE:   GCN CIRCULAR
NUMBER:  30235
SUBJECT: Swift ToO Observations of HAWC transient J0020+3108
DATE:    21/06/15 00:00:04 GMT
FROM:    Noel Klinger at PSU  <njk5441@psu.edu>

Swift performed a follow-up observation of the HAWC transient J0020+3108
(RA,Dec = 5.0800,31.1400) reported by Ayala et al. (2021; GCN # 30183) on
2021-06-11 between 18:33 and 20:10 (for 2.02 ks).

One uncataloged X-ray source, Swift J002003.2+310902.3, was detected
(S/N=1.8; 4.6(+2.0, -1.6)e-3 counts/s) at 5.013333,+31.150639 (7.1
arcsecond uncertainty), which is 3.5 arcminutes from the position of the
HAWC transient and thus within its 5.4 arcminute positional uncertainty.
The X-ray source is consistent with the position of quasar SDSS
J002003.33+310858.5 (aka Gaia DR2 2862347659832985728).  This quasar was
detected in the UVOT image (S/N=17.8) and exhibited a UVW1 magnitude 19.96
+/- 0.09 (AB).

Another uncataloged X-ray source, Swift J002054.1+310459.4, was detected
(S/N=2.2; 8(+2.8, -2.3)e-3 counts/s) at 5.225500, 31.083167 (5.7 arcsecond
uncertainty), which is 8.2 arcminutes away from the HAWC transient (and
therefore outside of its radius of positional uncertainty).  In this
observation, this source was outside of the UVOT field of view.