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Line profile analysis of the Delta Scuti star HD2724=BB Phe: mode identification and amplitude variations

Luciano Mantegazza·Ennio Poretti
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Abstract

The line profile variations of the Delta Scuti star HD 2724=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.

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Luciano Mantegazza, Ennio Poretti. 1999-05-26. Line profile analysis of the Delta Scuti star HD2724=BB Phe: mode identification and amplitude variations. https://doi.org/10.1051/0004-6361%3A20021456

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