Radial velocities of the cepheid X Cygni.
Abstract
A radial-velocity curve based on 17 coude spectra shows the following results when compared with other velocities: (1) no variation in mean velocity, implying no detectable companion; (2) no phase shifts if a period of 16.3861 days is used, indicating a constant period; (3) probably no variation in the shape of the velocity curve except perhaps at phases 0.55-0.80. Strong lines show a greater expansion by roughly one atmospheric scale height than moderate-strength lines, but it is not clear whether they show a similar greater contraction.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- June 1978
- DOI:
- Bibcode:
- 1978PASP...90..309A
- Keywords:
-
- Cepheid Variables;
- Radial Velocity;
- Stellar Spectrophotometry;
- Line Spectra;
- Phase Shift;
- Stellar Spectra;
- Astrophysics;
- Cepheids:Pulsations;
- Cepheids:Radial Velocities