A study of bright southern slowly pulsating B stars^*,**

II. The intrinsic frequencies

Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 B, 3001 Leuven, Belgium

Corresponding author: P. De Cat, Peter.DeCat@ster.kuleuven.ac.be

Received: 7 May 2002
Accepted: 19 July 2002

Abstract

We present the results of detailed frequency analyses of a sample of thirteen confirmed slowly pulsating B stars. Our analysis is based on a combination of elaborate photometric and spectroscopic data-sets. The original sample consists of a mixture of five confirmed slowly pulsating B stars and twelve candidate slowly pulsating B stars discovered thanks to the photometric measurements of the HIPPARCOS satellite. HD 55522 and HD 131120 turn out to be chemically peculiar stars. HD 169978 and HD 69144 are two ellipsoidal variables for which no intrinsic variability is found. At least nine of the thirteen studied slowly pulsating B stars are multi-periodic. For HD 74195, HD 85953, HD 123515 and HD 215573, the observed frequency spacings suggest that we are dealing with frequency multiplets. For the apparent mono-periodic binary HD 24587, it is not clear if the observed variations are induced by stellar pulsation and/or by rotation modulation. We highlight the statistical character of the observed pulsational properties of our sample.