[vsnet-campaign-dn 4479] Four new CVs in HS survey

[Taichi Kato]

Four new CVs in HS survey

   Although none of them is an SU UMa-type candidate ;-), visual monitoring
of their long-term behavior is well within reach.  These names have already
been incorporated in the VSNET summary system, and we are happy to receive
forthcoming observations.

Paper: astro-ph/0507342
Date: Thu, 14 Jul 2005 09:46:00 GMT   (929kb)

Title: HS0139+0559, HS0229+8016, HS0506+7725 and HS0642+5049: Four new
  long-period cataclysmic variables
Authors: A. Aungwerojwit, B.T. Gaensicke, P. Rodriguez-Gil, H.-J. Hagen, E.T.
  Harlaftis, C. Papadimitriou, H. Lehto, S. Araujo-Betancor, U. Heber, R.E.
  Fried, D. Engels and S. Katajainen
Comments: 12 pages, 17 figures, Astronomy and Astrophysics in press,
  low-quality figures to comply with astro-ph size limit
\\
  We present time-resolved optical spectroscopy and photometry of four
relatively bright (V~14.0-15.5) long-period cataclysmic variables (CVs)
discovered in the Hamburg Quasar Survey: HS0139+0559, HS0229+8016, HS0506+7725
and HS0642+5049. Their respective orbital periods, 243.69+-0.49min,
232.550+-0.049min, 212.7+-0.2min and 225.90+-0.23min are determined from radial
velocity and photometric variability studies. HS0506+7725 is characterised by
strong Balmer and He emission lines, short-period (~10-20min) flickering and
weak X-ray emission in the ROSAT All Sky Survey. The detection of a deep low
state (~18.5) identifies HS0506+7725 as a member of the VY Scl stars.
HS0139+0559, HS0229+8016 and HS0642+5049 display thick-disc like spectra and no
or only weak flickering activity. HS0139+0559 and HS0229+8016 exhibit clean
quasi-sinusoidal radial velocity varations of their emission lines but no or
very little orbital photometric variability. In contrast, we detect no radial
velocity variation in HS0642+5049 but a noticeable orbital brightness
variation. We identify all three systems either as UX UMa-type novalike
variables or as Z Cam-type dwarf novae. Our identification of these four new
systems underlines that the currently known sample of CVs is rather incomplete
even for bright objects. The four new systems add to the clustering of orbital
periods in the 3-4h range found in the sample of HQS selected CVs, and we
discuss the large incidence of magnetic CVs and VY Scl/SW Sex stars found in
this period range among the known population of CVs.
\\ ( http://arXiv.org/abs/astro-ph/0507342 ,  929kb)