[vsnet-alert 19859] CSS_J162117.4+441254 and similar Catalina variables

[Denis Denisenko]

Following the detection of an outburst from 2MASS_J16211735+4412541 by CRTS
(Drake et al., ATel #9112) I have searched for other short-period variables
from Catalina surveys with the similar properties in ultraviolet. Among 136
candidate ellipsoidal variables with P below 0.22d (Drake et al., 2014) 6
objects have (FUV-NUV) color index less than 1.0 in GALEX GR6/GR7 data
release. There may be additional cataclysmic variables hiding among those
ELL type variables.

Here is the list of these objects with GALEX UV magnitudes added. Note that
GR6 values given here may differ from blue points on Figure 5 of ApJ Vol.
790, p.157 paper by A. Drake et al. (2014) since they were plotted using
FUV and NUV magnitudes from an earlier GR5.

Catalina variable name | GALEX UV source name | Period | Var. range | FUV |
NUV
--------------------------------------------------------------------------------
CSS_J162117.4+441254 = GALEX J162117.4+441254  0.207852  14.80(0.50) 20.13
19.65
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CSS_J224134.8+253648 = GALEX J224134.8+253650  0.15738   16.41(0.29) 22.02
21.70

CSS_J222918.9+185340 = GALEX J222918.9+185340  0.189184  16.41(0.36) 20.30
19.63
Very asymmetric light curve for a simple ellipsoid

CSS_J093508.0+270049 = GALEX J093508.0+270049  0.2010344 16.03(0.28) 18.55
18.20
(Eclipsing white dwarf)

CSS_J171525.8+124852 = GALEX J171525.9+124850  0.21548   17.46(0.17) 21.70
21.86
May be a CV in the period gap (0.107741d) or HADS variable

CSS_J231909.5+082832 = GALEX J231909.6+082833  0.215519  15.67(0.25) 20.78
19.79
1RXS J231909.9+082832 (0.0203+/-0.0086 cnts/s HR1=0.38+/-0.49
HR2=0.61+/-0.48)
May be a CV in the period gap (0.107760d)

CSS_J084422.3+175008 = GALEX J084422.2+175008  0.215532  15.56(0.22) 19.12
19.20
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The variables in this list are definitely worth monitoring and checking the
archival data for possible outbursts.

Denis Denisenko
Sternberg Astronomical Institute of Moscow State University