CH Cygni and Other Symbiotic Stars with Low Luminosity Hot Components

Abstract

Some aspects of the recent activity period of the peculiar symbiotic binary CH Cyg, which has ejected both bipolar jets and discrete centrifugal outflows, are discussed.In symbiotic binaries, the red giant's wind is accreted onto the white dwarf. High luminosity of the hot components (Lhot ~103L⊙, reaching ~104L⊙ in the outbursts) (Mikołajewska 2003; Sokoloski 2003) indicates that the accreted matter undergoes thermonuclear burning. There are about 10 symbiotic stars which have ejected high-velocity, collimated, bipolar jets. Some of them show flickering of the optical light on the time scale of minutes. Both jet ejection and flickering indicate that an accretion disk should be present in those systems. Jet emitting symbiotic stars seem to have lower luminosity of the hot component ( ~1 – 100 L⊙) than in most other symbiotics.