The amplification of solar-line asymmetries by rotation
Abstract
The effect of rotation on granulation-induced line asymmetries is examined by computing composite, rotationally-broadened flux profiles from a grid of observed solar center-to-limb intensity profiles. After first demonstrating that the composite profiles are in reasonable agreement with profiles observed from the full solar disk, it is shown that rotation enhances these asymmetries. When the rotational velocity exceeds the half width of the intensity profile, the effects magnify rapidly. Using the bisector function as a measure of the asymmetries, it is found that the deviations from symmetry increase roughly as the rotational velocity squared. This study leads to the general conclusion that any curvature in the bisector function of a line having a stellar origin will be exaggerated by rotation.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- April 1987
- DOI:
- 10.1086/131987
- Bibcode:
- 1987PASP...99..297S
- Keywords:
-
- Asymmetry;
- Solar Granulation;
- Solar Rotation;
- Solar Spectra;
- Line Spectra;
- Solar Limb;
- Stellar Rotation;
- Stellar Spectra;
- Solar Physics