The chromospherically active binary star EI Eridani: I. Absolute dimensions
✍ Scribed by A. Washuettl; K.G. Strassmeier; T. Granzer; M. Weber; K. Oláh
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 270 KB
- Volume
- 330
- Category
- Article
- ISSN
- 0004-6337
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✦ Synopsis
We present a detailed determination of the astrophysical parameters of the chromospherically active binary star EI Eridani. Our new radial velocities allow to improve the set of orbital elements and reveal long-term variations of the barycentric velocity. A possible third-body orbit with a period of ≈ 19 years is presented. Absolute parameters are determined in combination with the Hipparcos parallax. EI Eri's inclination angle of the rotational axis is confined to 56. • 0 ± 4. • 5, its luminosity class IV is confirmed by its radius of 2.37 ± 0.12 R . A comparison to theoretical stellar evolutionary tracks suggests a mass of 1.09 ± 0.05 M and an age of ≈ 6.15 Gyr. The present investigation is the basis of our long-term Doppler imaging study of its stellar surface.