GCN Circular 17541

L. M. Z. Hagen (PSU) and A. Y. Lien (GSFC/UMBC)
report on behalf of the Swift/UVOT team:


A point source is detected by UVOT that is consistent with the XRT
counterpart and 2.5 arcsec from the XMM-Newton source discussed in
Evans et al. (GCN Circ. 17536
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 ).  This source is also seen in archival
DSS imaging.  It is unclear if this is the same object detected by XRT
or a serendipitous source.  Given how crowded the field is, it is also
likely that the UVOT source is comprised of multiple individual sources.
The coordinates of the UVOT source are
   RA(J2000) = 00:45:14.76 = 11.31150
   DEC(J2000) = +41:50:35.2 = 41.84311

Preliminary detections and 3-sigma upper limits using the UVOT
photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373)
for the available exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white              102         4151          369         19.22+-0.13
v                  592         4562          216        >18.53
b                  518         5241           96        >19.08
u                  261         5177          461         18.60+-0.15
uvw1               641        79666         5117         18.64+-0.05
uvm2               617        45953         1237         18.94+-0.13
uvw2               568         4357          216         18.99+-0.27

The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.06 in the direction
of the source (Schlegel et al. 1998).

This field has also been observed previously by UVOT as part of a
different observing campaign, primarily in 2013 and 2014. The
stacked images have the following detections:

Filter      Exp(s)        Mag

v            1406     19.04+-0.19
b            1445     19.77+-0.15
u           27521     18.65+-0.03
uvw1        52236     18.57+-0.02
uvm2        58908     18.65+-0.03
uvw2        65719     18.61+-0.02

These indicate possible variability of the source, but further
analysis will be required to confirm this.