Abundance analysis of roAp stars. I. α Circin

Author(s)
Friedrich Kupka, Tanya A. Ryabchikova, Werner Wolfgang Weiss, Rainer Kuschnig, J Rogl, Gautier Mathys
Abstract

Based on high resolution, low noise spectroscopy in the spectral region from 4200Å to 6700Å we derived Teff=7 900 ± 200 K, log g=4.2 ± 0.15. v sin(i)=12.5(-0.5. +1.5)km s-1, and elemental abundances for the rapidly oscillating (ro)Ap star α Cir(HD 128898, HR 5463). We used the spectrum synthesis and the equivalent width technique and confirmed the presence of a magnetic field in α Cir. The underabundance of C, N, and O, and the overabundances of rare-earth and some other heavy elements are comparable to other cool Ap-stars. The most important peculiarity is that of Co, which is almost as overabundant as Cr, the most overabundant iron peak element in cool Ap-stars.

Organisation(s)
Department of Astrophysics
External organisation(s)
Russian Academy of Sciences, European Southern Observatory (Germany)
Journal
Astronomy & Astrophysics
Volume
308
Pages
886-894
No. of pages
9
ISSN
0004-6361
Publication date
1996
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/e42ee060-ec96-47d0-a499-3261904e67ee