Classification of N-Type Carbon Stars.
Abstract
Carbon stars are in an advanced state of evolution and are of interest for understanding the rapid evolutionary processes during late stages of stellar evolution. They are cool (T<4000K) stars with an atmospheric carbon to oxygen ratio (C/O) greater than one. Most other classes of stars exhibit atmospheric C/O < 1. Low resolution spectrophotometry has been used to examine the relationship between spectral class and effective temperatures in a sample of eleven cool carbon stars. Using effective temperatures from lunar occultation observations of Tsuji and Ridgeway et al, CN and C2 features have been examined for their utility as classification criteria. It is found that C2 strength is not a reliable temperature classification parameter, while CN should be useful. Comparison of the carbon star classification systems of Keenan and Morgan and that of Richer with recent derived temperatures and the results of this study indicates that the Richer classification system more accurately reflects the temperatures of cool carbon stars.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1986
- Accession Number
- ADA171399
Entities
People
- William V. Bollwerk
Organizations
- Naval Postgraduate School