The Structural Effects of Rotation in Low Mass Stars

We present theoretical models of rotating low mass stars (0.1 1.0 M⊙ ) to demonstrate the effect of rotation on the effective temperature and luminosity of stars. The range of rotation rates in our models corresponds to the observed rotation rates in young low mass stars. Rotation lowers the effective temperature and luminosity of the models relative to standard models of the same mass and composition. We find that the decrease in Teff and L can be significant at the higher end of our mass range, but becomes small below 0.4 M⊙ . The effects of different assumptions about internal angular momentum transport are discussed. Formulae for relating Teff to mass and vrot are presented. We demonstrate that the kinetic energy of rotation is not a significant contribution to the luminosity of low mass stars. Subject headings: stars: evolution – stars: rotation – stars: interiors – stars: formation – low mass stars