SCYON Abstract

Received on September 16 2005

A statistical analysis of chemically peculiar stars in open clusters

AuthorsM. Netopil(1), E. Paunzen(1), H. Pöhnl(1), H.M. Maitzen(1), I.Kh. Iliev(2), O.I. Pintado(3), M. Rode-Paunzen(1), M.L. Alvear-Gomez(1)
Affiliation(1) Institute for Astronomy, University of Vienna, Austria
(2) Institute of Astronomy, National Astronomical Observatory, Smolyan, Bulgaria
(3) Departamento de Fisica, Facultad de Ciencias Exactas y Tecnologia, Universidad Nacional de Tucuman, Argentina
Submitted toAstronomy & Astrophysics


The chemically peculiar (CP) stars of the upper main sequence are excellent test objects to study the effects of diffusion, mass-loss, meridional circulation and global magnetic fields over a temperature range from 24000 to 6000K (9Mo > M > 1.5Mo). Due to the chemical peculiarity, the standard calibrations methods derived for apparent normal type stars often fail, or at least give erratic results for this group of objects. We have therefore chosen CP stars that are members of galactic open clusters because parameters like the age, distance, and reddening for open clusters can be determined in a statistic way for up to hundreds of members which minimizes the errors introduced by the chemical peculiarity. In total, 276 classified CP stars in 78 open clusters were found after a careful analysis of membership criteria based on kinematic data and all available color-color diagrams. The incidence and characteristics of the different subgroups are analyzed according to the temperature range, age, metallicity and location within the Milky Way.