1982/12/01 by L. Celis S. · 12 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Effective temperature #Hertzsprung–Russell diagram #History and Developments in Astronomy #Main sequence #Photometry (optics) #Physics #RADIUS #Red giant #Stars #Stellar classification #Stellar evolution #Stellar, planetary, and galactic studies #Variable star
paper · doi:10.1086/113268
published in The Astronomical Journal 87, 1791 (Institute of Physics)
openalex publication_date 1982/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/02/25
In all phases of the light cycle of red variables stars, their near-infrared colors define a narrow sequence in the two color (V - R, R - I) diagram. This does not occur with other cool variable stars of types Ce, Se, and Ne. The position of a red variable on this sequence is very sensitive to the Me spectral type. The colors are molecular absorption indices, fundamentally of TiO, rather than indices of the color temperature. In general, the photometric magnitudes for a given Me star result from surfaces of different stellar radius and depend on the presence or absence of absorbing bands in the observed spectral continuum. This result is discussed in terms of amplitudes, radius, visual absolute magnitudes, and effective temperature, all of them free of or affected by TiO. Finally, these results give more information on which to build a model whose radial structure would have a relatively high stellar effective temperature and several cool covers of TiO molecules.