A&A Supplement series, Vol. 123, May II 1997, 93-101
Received June 14; accepted September 10, 1996
E. Paunzen , W.W. Weiss , U. Heiter , and P. North
Send offprint request: E. Paunzen
Institut für Astronomie, Türkenschanzstr. 17, A-1180 Wien, Austria
Institut d'Astronomie de l'Université de Lausanne, CH-1290 Chavannes-des-Bois, Switzerland
Bootis stars challenge our understanding of diffusion and accretion processes
to stars and their circumstellar environment, and they are interesting
of the classical instability strip.
Attempts to derive group
properties with statistical methods are severely limited by the small
number of unambiguously
identified Bootis stars. In general, the subject appears to be obscured by
incorrect memberships and it is therefore essential to provide
a sufficiently large catalogue of definitive group members before modeling
the Bootis phenomenon.
This paper describes the first steps towards this goal, based on our current knowledge of well investigated members, leading to a concise definition of Bootis stars: PopI hydrogen burning metal poor (except of C,N,O and S) A-type stars. The definition does not depend on phenomenological features, like flux depressions, colour excesses, values, etc.
Based on a new homogeneous catalogue with 45 Bootis stars, we discuss classification criteria which can be used for a spectroscopic and photometric all-sky survey for Bootis stars in the field and in clusters of different ages.
keywords: astronomical data bases -- catalogues; stars -- Bootis\; stars -- chemically peculiar; stars -- early type