0000000000131744
AUTHOR
Raivis Spēlmanis
A search for diffuse absorption bands in carbon-rich stars -- I. Barium and related stars
The results of a search for interstellar and circumstellar absorption lines in high-resolution optical spectra of seven late-type stars are presented. All these stars are single-lined spectroscopic binaries with unseen companions, presumably white dwarfs. Some residual material indicative of recent mass transfer from an asymptotic giant branch (AGB) star might still be associated with the systems. Peculiar energy distribution and the sodium D 1 and D 2 lines give direct evidence about the material in the line of sight in some cases. Absorption features of simple carbon-bearing molecules (C 2 , CN) have been detected in most of the examined stars, confirming a carbon-rich nature of the corre…
CIT 6: The Early Phase of PPN?
Photometric and spectroscopic studies for one of the early phase candidate for proto-planetary nebulae, the dust enshrouded extreme carbon star CIT 6, are presented.