Multicolor Photometry of Long Period Variables
Abstract
Multicolor photometry is made of sixty seven late type stars over wavelengths ranging from 0.3μ to 10.2μ. The observations enable one to distinguish between classes M, S and C. The M and S stars unreddened by interstellar extinction can be separated and their spectral types estimated by multicolor photometry while spectral sub-types for reddened M stars by interstellar extinction can also be derived by our photometry. The computed effective temperatures range from 3325°K down to 1650°K and the bolometric corrections range from -2.2 to -11.0 magnitude. Possibly Carbon stars have brighter M_v than the M and S stars of the same effective temperature. Multicolor photometry is substantially affected by the ratio O/C. Hence the bolometric corrections and effective temperatures derived from it will depend on the ratio O/C. The effect of this ratio in B-V, for example, is to make S stars intrinsically redder than M stars for the same temperature. Again, this ratio will cause the Carbon stars to appear even much redder intrinsically than cither M or S stars of the same temperature.
- Publication:
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Boletin de los Observatorios Tonantzintla y Tacubaya
- Pub Date:
- April 1967
- Bibcode:
- 1967BOTT....4..114M
- Keywords:
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- Photometry