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| Paper: |
Populating the HR Diagram with the Hipparcos Catalogue |
| Volume: |
167, Harmonizing Cosmic Distance Scales in a Post-Hipparcos Era |
| Page: |
101 |
| Authors: |
Casertano, Stefano; Ratnatunga, Kavan U. |
| Abstract: |
We present a detailed description of the magnitude, color, kinematics and geometry of the stellar populations in the solar neighborhood, as derived from the blue stars in the Hipparcos Catalogue ( 0 < B-V < 0.8 ). In our representation, the HR diagram is divided into three main components: a narrow main sequence, a broader and brighter component representing stars just evolving from the main sequence, and the luminous stars, which represent a continuum from subgiants to supergiants. Velocity-wise, three separate components are also needed: a young population with very low velocity dispersion ( σr ~ 20 -25 kms), an older disk population ( σr ~ 30-50), and the high velocity component, which includes the spheroid/halo population and possibly also the thick disk. |
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