1RXS J180834.7+101041 is a new cataclysmic variable with non-uniform disc

Abstract

Abstract.Results of photometric and spectroscopic investigations of the recently discovered disc cataclysmic variable star 1RXS J180834.7+101041 are presented. Emission spectra of the system show broad double peaked hydrogen and helium emission lines. Doppler maps for the hydrogen lines demonstrate strongly non-uniform emissivity distribution in the disc, similar to that found in IP Peg. It means that the system is a new cataclysmic variable with a spiral density wave in the disc. Masses of the components (M WD = 0.8 ± 0.22M ⊙ and M RD = 0.14 ± 0.02 M ⊙ ), and the orbit inclination (i = 78 • ± 1.• 5) were estimated using the various well-known relations for cataclysmic variables.

Hunting for eclipses: high-speed observations of cataclysmic variables

“…1RXS J180834.7+101041: Originally classified as a polar (Denisenko, Kryachko & Satovskiy 2008), spectra later showed that it has an accretion disc (Bikmaev & Sakhibullin 2008). Eclipses have been studied previously (Yakin et al 2010;Southworth & Copperwheat 2011), but attempts to measure the system parameters have had limited success because the white dwarf itself might not be eclipsed. We found strong flickering and only weak eclipse structure, possibly associated solely with the accretion disc and bright-spot but not the white dwarf.…”

Evidence for mass accretion driven by spiral shocks onto the white dwarf in SDSS J123813.73–033933.0

“…So far, the presence of spiral density shocks in the accretion disc of quiescent CVs has only been determined indirectly (e.g. Yakin et al 2010;Bisikalo 2011;Kononov et al 2012) and only from the analysis of Doppler maps. Our results represent the first direct evidence for the presence of such shocks during quiescence and their ability to modulate the accretion flow onto the white dwarf.…”