P. Rodríguez-Gil, L. Schmidtobreick, K. S. Long, T. Shahbaz, B. T. Gänsicke, M. A. P. Torres
We review our knowledge of the origin and phenomenology of low states (also
known as VY Scl states) in cataclysmic variables, making special emphasis on
the cataclysmic variable population found just above the period gap. This
orbital period range between approximately 3 and 4 hours is the preferred land
for the elusive SW Sextantis stars, which are believed to be about to enter the
gap when their donor stars become fully convective. Despite their main role in
our understanding of the whole picture of cataclysmic variable evolution, the
study of their component stars is almost impossible due to the extreme veiling
brightness of the accretion disc during the high state. Here we present the
first steps toward the characterisation of the white dwarfs and the donor stars
in these VY Scl systems in the low state, and the discovery of sporadic
accretion events and satellite emission lines like those observed in the AM Her
systems in the low state, which are likely related to magnetic activity of the
fast rotating secondary stars.
View original:
http://arxiv.org/abs/1112.0902
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