Evolutionary Tracks in the H-R Diagram Astrophysics Nucleosynthesis and Stellar Evolution Evolutionary Tracks in the H-R Diagram Questions Is there an upper limit to the mass of a star above which it would not enter the AGB? If so, why? At what point in a star's life are they classified as AGB? How are AGB stars formed? What three properties of stars can astronomers determine by analyzing the spectrum of the stars light? Nucleosynthesis and Stellar Evolution View all chapters Nuclear Fusion Models of the Nucleus Main-Sequence Burning Helium-Burning Phase Advanced Nuclear Burning Evolutionary Tracks in the H-R Diagram Stellar Clusters Stellar Remnants Novae and Supernovae Prev Next