Topic – this semester
• Find all chemically peculiar (CP) stars which
are members of open clusters or stellar
associations
• What do we need?
1. Parallaxes, proper motions, coordinates and
diameters of star clusters
2. Parallaxes, proper motions and coordinates of CP
stars
3. Determination of the true members
4. Plot the colour-magnitude diagrams as check
Classical chemically peculiar stars
• Upper main sequence stars, spectral region B2
to F2
• Low rotational rate (< 100 km/s)
• Some have stable and organized stellar
magnetic field
• Diffusion and stratification
• Spots
Classical chemically peculiar stars
What can we learn from CP stars in
open clusters?
• Do we find CP stars at all ages?
• Are there very young, especially magnetic CP
stars existing?
• Timescales for the formation of the local
stellar magnetic field and diffusion.
• Is there an influence of the local metallicity on
the peculiarity?
• Single star determination correct?