Indicators of Mass in Spherical Stellar Atmospheres
Document Type
Article
Publication Date
4-1-2013
Description
Mass is the most important stellar parameter, but it is not directly observable for a single star. Spherical model stellar atmospheres are explicitly characterized by their luminosity (L*), mass (M*), and radius (R*), and observations can now determine directly L* and R*. We computed spherical model atmospheres for red giants and for red supergiants holding L* and R* constant at characteristic values for each type of star but varying M*, and we searched the predicted flux spectra and surface-brightness distributions for features that changed with mass. For both stellar classes we found similar signatures of the stars' mass in both the surface-brightness distribution and the flux spectrum. The spectral features have been use previously to determine log10 (g), and now that the luminosity and radius of a non-binary red giant or red supergiant can be observed, spherical model stellar atmospheres can be used to determine a star's mass from currently achievable spectroscopy. The surface-brightness variations of mass are slightly smaller than can be resolved by current stellar imaging, but they offer the advantage of being less sensitive to the detailed chemical composition of the atmosphere.
Citation Information
Lester, John B.; Dinshaw, Rayomond; and Neilson, Hilding R.. 2013. Indicators of Mass in Spherical Stellar Atmospheres. Publications of the Astronomical Society of the Pacific. Vol.125(926). 335-343. https://doi.org/10.1086/670255 ISSN: 0004-6280