Spectroscopic observations of yellow supergiants: I. Radial pulsations of Rho Cassiopeiae.
Abstract
High-resolution Reticon spectra of the F8 Ia-0 supergiant ρ Cas providing lines of differing excitation potential are employed to construct radial-velocity curves which reveal a semiregular pulsation of the atmosphere. Analysis of line-doubling episodes supports the presence of a dominant radial pulsation mode with a period around 500 days, significantly longer than the radial fundamental mode predicted on the basis of Cepheid-like PLC relations for a star evolving to the red supergiant region. Predicted periods for fundamental radial pulsations in stars returning toward the blue supergiant region are comparable to the observed quasi-period.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- October 1986
- DOI:
- 10.1086/131844
- Bibcode:
- 1986PASP...98..914S
- Keywords:
-
- Radial Velocity;
- Stellar Oscillations;
- Stellar Spectra;
- Supergiant Stars;
- Variable Stars;
- Light Curve;
- Line Spectra;
- Stellar Evolution;
- Astrophysics;
- Pulsations:Supergiants;
- Radial Velocities:Supergiants;
- Spectra:Supergiants;
- Supergiants:Pulsations;
- Supergiants:Radial Velocities;
- Supergiants:Spectra