90 likes | 150 Views
Our Sun. III. Present and Future (1993ApJ_418_475s). Jae Gyu, Byeon. Contents. Methods Values of M, R, L, and t Opacities Presolar Helium and the Mixing Length Mass Loss Results The Sun ’ s evolution in the HR diagram The Sun ’ s Mass Loss Convection The Sun ’ s Radial Excursions
E N D
Our Sun. III. Present and Future(1993ApJ_418_475s) Jae Gyu, Byeon
Contents • Methods • Values of M, R, L, and t • Opacities • Presolar Helium and the Mixing Length • Mass Loss • Results • The Sun’s evolution in the HR diagram • The Sun’s Mass Loss • Convection • The Sun’s Radial Excursions • Conclusions
Methods • Values of M⊙, R⊙, L⊙, and t⊙ • The solar mass is M⊙ = 1.9891 × 1033 g • The solar radius at an optical depth of 0.001 is R⊙ = 6.9598 × 1033 cm • The Solar luminosity L⊙ = 3.854 × 1033 erg s-1 • T⊙ = 4.55 Gyr • Opacities • Use the Los Alamos Opacity from Keady(1985) • At low temperatures, use the molecular opacities by Keady • Modify recent molecular opacities of Sharp(1992)
Methods • Presolar Helium and the Mixing Length • Presolar helium abundance, Y = 0.274 • Mixing Length parameter, α = 2.10 • Metallicity Z = 0.01954 • Mass Loss • η is the mass-loss parameter • Normalized from the RGB mass loss inferred from (low mass) globular cluster horizontal branch stars • Solar mass loss of 0.275 M⊙ on the RGB and 0.184 M⊙on the AGB