TiI .LAMBDA.8719 and (CI) .LAMBDA.8727 Lines in Carbon Stars.

The R Coronae Borealis stars - carbon abundances from forbidden carbon lines

Spectra of several R Coronae Borealis (RCB) stars at maximum light were examined for the [C i] 9850Å and 8727Å absorption lines. The 9850Å line is variously blended with a Fe ii and CN lines but positive identifications of the [C i] line are made for RCrB and SUTau. The 8727Å line is detected in the spectrum of the five stars observed in this wavelength region. Carbon abundances are derived fro...

Making carbon in stars

The triple alpha (3α) process plays an important role in the production of C in stars. Its rate is known with an accuracy of about 12%. We examine the corresponding uncertainties introduced in the description of pre-supernova stars, of nucleosynthesis in a core-collapse SN explosion, and of the production of C during the third dredge-up in asymptotic giant branch (AGB) stars. For the AGB case w...

Carbon Stars

In this review we rst describe basic information for carbon stars starting with the most recent spectral classi cation system of P.C. Keenan and luminosities derived from data in the Hipparcos Catalogue. For the SRb and Lb variables MK = 6:8 1:2 (21 stars). Only two R stars (non-variables) have measured K magnitudes and showMK = 5:2. The four N stars show MV = +0:76 1:06. Using the Magellanic C...

TII Best Paper Awards 2012 :

Lithium in LMC Carbon Stars

Nineteen carbon stars that show lithium enrichment in their atmospheres have been discovered among a sample of 674 carbon stars in the Large Magellanic Cloud. Six of the Li-rich carbon stars are of J-type, i.e., with strong C isotopic features. No superLi-rich carbon stars were found. The incidence of lithium enrichment among carbon stars in the LMC is much rarer than in the Galaxy, and about f...