EX Hya : physical parameters derived from simultaneous spectroscopy and photometry.
Abstract
Simultaneous photometry and high time resolution spectrophotometry used to determine the orbital characteristics of the eclipsing dwarf nova system EX Hydrae show that the 67-min photometric period appears, spectroscopically, as a modulation of emission-line intensities. A new analysis of the eclipse timing reveals a constant orbital period, while analysis of the 67-min variation shows a significant period increase, and emission-line profiles are found to vary at 1/2 of the 67-min period as well as the orbital period. After a discussion of models for the 67-min variation, standard assumptions concerning the secondary component are found to suggest masses of 1.4 and 0.17 solar masses for the binary components on the basis of a 58 + or - 9 km/sec radial velocity half-amplitude.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1982
- DOI:
- 10.1086/160109
- Bibcode:
- 1982ApJ...258..576G
- Keywords:
-
- Dwarf Novae;
- Eclipsing Binary Stars;
- Ephemerides;
- Orbital Elements;
- Variable Stars;
- X Ray Sources;
- Balmer Series;
- Continuous Spectra;
- High Resolution;
- Radial Velocity;
- Spectral Line Width;
- Stellar Mass;
- Stellar Models;
- Stellar Spectrophotometry;
- Astrophysics