our sun. iii. present and future (1993apj_418_475s)
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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 - PowerPoint PPT PresentationTRANSCRIPT
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) glob
ular cluster horizontal branch stars– Solar mass loss of 0.275 M⊙ on the RGB and 0.184 M⊙
on the AGB
The Sun’s evolution in the HRD
The Sun’s evolution in the HRD
The Sun’s Mass Loss
Convection
The Sun’s Radial Excursions