A model atmosphere analysis of the Ap star HR 465.
Abstract
A detailed model atmosphere analysis of the Ap spectrum variable HR 465 is presented for three well- spaced epochs. The analysis is based on 2 A/mm spectrograms secured at the coud focus of the Lick 120-inch telescope and a continuous energy distributed obtained with the University of Michigan 52-inch telescope. A representative model characterized by 0 = 0A75 at log T5000 = -0.20, by log g = 3.7 and by = 4km/s was selected from a grid by comparison of observed and theoretical continuous energy distributions, hydrogenline profiles and metal-line profiles. Overabundances of the order of 108 or more are found for the rare earths, Mo and Nb; of order 108 for Sr and Zr, and of order 10 for the iron-peak elements. Smaller overabundances are found for Al and Si. The results of the abundance analysis are discussed in terms of several current theories proposed to explain the Ap abundance anomalies. Key words: model atmosphere - abundances - Ap star
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 1972
- Bibcode:
- 1972A&A....19..248A