## Hot subdwarf stars: galactic orbits and distribution perpendicular to the plane
^{1} Sternwarte, Univ. Bonn, Auf dem Hügel 71, D-53121
Bonn, Germany^{2} Observatoire de Bordeaux, CNRS/INSU, F-33270 Floirac,
France
The spatial distribution and the population nature of subdwarf B type stars in the galaxy is investigated based on the kinematics of these stars. With new and available proper motions, radial velocities, and distances, the orbits of 41 stars have been calculated using a galactic mass model. The orbits are well behaved and 10 stars reach to kpc. Many orbits are very eccentric, reaching in to just 2 kpc from the galactic centre, or veering out to beyond 20 kpc. None of the stars can be identified uniquely as classical Population II objects. The average eccentricity A statistical analysis of the orbits shows that the subdwarf stars
have a spatial distribution in The distribution in
## Contents- 1. Introduction
- 2. The data
- 2.1. New absolute proper motions
- 2.2. Radial velocities
- 2.3. Distances
- 3. Orbits, populations
- 4.
*z*-Probability and*z*-distribution - 5. Conclusions
- Acknowledgements
- References
© European Southern Observatory (ESO) 1997 Online publication: April 6, 1998 |