A study of the occurrence of singly ionized calcium emission in late-type spectroscopic binary stars.
Abstract
A sample of spectroscopic binaries with published orbits is studied spectroscopically at high dispersion for the occurrence and properties of emission in the Ca II H and K lines. The sample contained 68 binaries with periods between 1 day and 40 years, and spectral types from F8 to K5, including main sequence, subgiant, and giant components. Eighteen systems were found to exhibit such emission, and all but two have periods under 100 days. However, there are 12 systems within the same period domain that are devoid of emission. Based upon radial velocity measurements, we demonstrate that the emission is chromospheric in origin, and we suggest that tidal-coupling effects have altered the 'acoustic' and the 'mechanical' wave energy transport mechanisms which are thought to heat the chromosphere.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1977
- DOI:
- 10.1086/154992
- Bibcode:
- 1977ApJ...211..836Y
- Keywords:
-
- Binary Stars;
- Emission Spectra;
- Late Stars;
- Stellar Spectra;
- Atmospheric Tides;
- Calcium;
- Chromosphere;
- Giant Stars;
- Main Sequence Stars;
- Tables (Data);
- Wave Propagation;
- Astronomy