Line profile analysis of the delta Scuti star HD 2724 = BB Phe: mode identification and amplitude variations
Abstract
The line profile variations of the delta Scuti star HD 2724equiv BB Phe were studied on the basis of new 189 high-resolution spectrograms covering 52 hours of observations on a baseline of 8.3 days. By combining these results with those of a previous campaign 13 pulsation modes were identified: 5 of them are both photometric and spectroscopic, 3 are purely spectroscopic and 5 purely photometric. For the first time it was possible to compare spectroscopic data taken in two different seasons: 6 modes were found to be common to both datasets and furthermore strong amplitude variations of the excited modes were detected. The fit of the line profile variations with a model of non-radial pulsating star allowed us to obtain a reasonable estimate of the inclination of the rotational axis and to propose the l,m typing of the spectroscopic modes. The frequency content resembles that of 4 CVn, a delta Sct star with similar physical parameters. Based on observations collected at the Coudé Auxiliary Telescope of the European Southern Observatory -- La Silla, Chile (Proposal 60.E-0113)
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- August 1999
- Bibcode:
- 1999A&A...348..139M
- Keywords:
-
- METHODS: DATA ANALYSIS;
- TECHNIQUES: SPECTROSCOPIC;
- STARS: INDIVIDUAL: HD 2724;
- STARS: OSCILLATIONS;
- STARS: VARIABLES: DELTA SCT