The secular and thermal spectrum of hydrogen-deficient carbon stars

Abstract

Applying the Riccati method to the secular problem, secular and thermal spectra of a 0.9 M⊙ HdC star are investigated in various evolutionary phases. The onset of shell burning is associated with a bewildering complexity of the thermal and secular spectrum and is interpreted using a simplified analytical model. Shell burning leads to the decoupling of different parts of the spectrum, one of which seems to be closely related to the strange mode II phenomenon.