Fourier analysis of Fe I lines in the spectra of the Sun, α Centauri A, Procyon, Arcturus, and Canopus.
Abstract
Spectral observations of Fe I lines with a 200000 resolution were used to determine turbulent velocities in the atmospheres of the Sun, α Cen A, Procyon (α CMi), Arcturus (α Boo), and Canopus (α Car) and estimate the rotation velocity (Vesin i) of Canopus. Isotropic microturbulent velocities (Vmi) and radial-tangential macroturbulent velocities (VmaRT) were found to be a quite suitable approximation to the velocity field in the atmospheres of all stars studied except Canopus. The average velocities Vmi and VmaRT are 0.8±0.1 and 2.6±0.3 km/s for the Sun as a star, 0.8±0.2 and 2.9±0.4 km/s for α Cen A, 0.8±0.3 and 5.9±0.2 km/s for Procyon, 1.0±0.2 and 4.6±0.3 km/s for Arcturus. The velocity field in the atmosphere of Canopus can be described by an anisotropic radial-tangential distribution of microturbulence (VmiRT = 2.1 km/s) and anisotropic macroturbulent velocities with greatly different radial and tangential components (Vmarad = 17±2 km/s and Vmatan = 1.3±1.0 km/s); Vesin i for Canopus is 3.5±0.2 km/s.
- Publication:
-
Kinematics and Physics of Celestial Bodies
- Pub Date:
- 1998
- Bibcode:
- 1998KPCB...14..169S
- Keywords:
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- Stellar Atmospheres: Turbulence;
- Stellar Atmospheres: Iron Lines;
- Velocities: Stellar Atmospheres;
- Solar Atmosphere: Velocities;
- Solar Atmosphere: Turbulence;
- Solar Atmosphere: Iron Lines