Aerts, C. ; De Cat, P. ; Peeters, E. ; Decin, L. ; De Ridder, J. ; Kolenberg, K. ; Meeus, G. ; Van Winckel, H. ; Cuypers, J. ; Waelkens, C.

published in Astronomy and Astrophysics, 343, pp. 872-882 (1999)

Abstract: The photometric experiment on Hipparcos has led to the discovery of, among other types of variables, a large amount of new Slowly Pulsating B Stars. We have selected twelve bright southern stars of this sample, together with five previously known Slowly Pulsating B Stars, for spectroscopic and photometric monitoring. These seventeen stars have spectral types ranging from B 2 up to B 9 and thus fully cover the instability strip. We here present the results of a preliminary analysis of our data and show that our sample is an extremely important one to perform seismology of intermediate-massive stars. In particular, we find that all but one of the selected stars exhibit clear line-profile variability. The broader-lined Slowly Pulsating B Stars tend to have more complex line-profile variations. One of the previously known Slowly Pulsating B stars was known to be a binary. Besides this star, another six of the selected Slowly Pulsating B stars turn out to be multiple systems. Five of these seven binaries have large rotational velocities and complicated line-profile variations with moving subfeatures. It is not yet clear whether or not the binarity results in a particular spectrum of excited modes. Based on observations collected with the CAT Telescope of the European Southern Observatory and with the Swiss Photometric Telescope of the Geneva Observatory, both situated at La Silla in Chile

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