Optical spectroscopy of X-Mega targets : II. The massive double-lined O-type binary HD93205
A new high-quality set of orbital parameters for the O-type spectroscopic binary HD 93205 has been obtained combining échelle and coudé CCD observations. The radial velocity orbits derived from the He iiλ4686 Å (primary component) and He iλ4471 Å (secondary component) absorption lines yield semi-amp...
| Autores: | , , , , , , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2001 |
| País: | Argentina |
| Institución: | Universidad Nacional de La Plata |
| Repositorio: | SEDICI (UNLP) |
| Idioma: | inglés |
| OAI Identifier: | oai:sedici.unlp.edu.ar:10915/2072 |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/2072 |
| Access Level: | acceso abierto |
| Palabra clave: | Ciencias Astronómicas Astrofísica binaries: general stars: early-type stars: individual: HD 93205 X-rays: stars |
| Sumario: | A new high-quality set of orbital parameters for the O-type spectroscopic binary HD 93205 has been obtained combining échelle and coudé CCD observations. The radial velocity orbits derived from the He iiλ4686 Å (primary component) and He iλ4471 Å (secondary component) absorption lines yield semi-amplitudes of 133±2 and 314±2 km s−1 for each binary component, resulting in minimum masses of 31 and 13 M⊙(q=0.42). We also confirm for the binary components the spectral classification of O3 V+ O8 V previously assigned. Assuming for the O8 V component a ‘normal’ mass of 22–25 M⊙ we would derive for the primary O3 V a mass of ‘only’52–60 M⊙ and an inclination of about 55° for the orbital plane. We have also determined for the first time a period of apsidal motion for this system, namely 185±16 yr using all available radial velocity data sets of HD 93205 (from 1975 to 1999). Phase-locked variations of the X-ray emission of HD 93205 consisting of a rise of the observed X-ray flux near periastron passage are also discussed. |
|---|