engleski

CH Cygni: A symbiotic star in its transition phase to quiescence

The transition period of symbiotic stars from the activity to the quiescent phase has not yet been sufficiently investigated. In order to establish the relation of such stars to the recurrent novae and on the other side, to the normal stars of the same spectral type, it is important to follow the spectrum also during the quiescent phases. The behaviour of the cool component of the symbiotic star CH Cygni over the two year period after its longest 1977-1986 outburst has been investigated in the optical spectral region.The results show that CH Cygni has been very close to the condition of optical quiescency and that the comparison with normal stars could predict its future behaviour. The relevant physical parameters, such as excitation temperature and microturbulent velocity, of M type stars 30 Her and beta And have been taken for reference. The curve of growth method with refined fitting procedure has been used.

symbiotic stars; CH Cyg; M type stars; quiescence

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