Surface imaging of late-type stars.
Abstract
The basic principles of stellar surface imaging techniques are discussed, and two ways of regularizing this ill-posed inverse problem are compared. Maximizing the information entropy means that minimum correlation between different points at the stellar surface should be expected, while the use of a Tikhonov regularization functional leads to the smoothest possible solution. Physical conditions in the stellar surface layers may favor the latter method, and the present simulation experiment shows that it does not produce small size, high contrast features below the spatial and temporal resolution of the data, which is typical of maximum entropy images. The technique is also illustrated by applying it to the FK Comae-type star HD 32918.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 1990
- Bibcode:
- 1990A&A...230..363P
- Keywords:
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- Imaging Techniques;
- Late Stars;
- Stellar Structure;
- Surface Properties;
- Giant Stars;
- Stellar Atmospheres;
- Stellar Models;
- Astrophysics