AST 1410H Stars

Stellar astrophysics is the best developed subject in all of astrophysics. Multiple physical processes have been brought into an organic synthesis here to successfully explain observations of stars, interstellar material, planets, and galaxies. As such, stellar astrophysics is one of the foundations of modern astrophysics. In addition to discussing the physical and astrophysical aspects of stars, we will also discuss major remaining puzzles in this area.

Course Outline:

Part I    Overview and Requisite physics, 4 wks

1. master equations, equilibria, timescales, mass-radius/mass-luminosity scaling; astronomical backgrounds, Hertzbrung-Russell diagram, common threads in stellar evolution, features in stellar evolution2. equation of state: fermions and bosons, pressure and energy density, ideal gas, (complete and partial) degenerate gas, radiation pressure, Boltzman distribution, Saha equation;3. heat loss: radiative diffusion, conduction, opacity sources, Schwarzschild and Ledoux criteria, mixing length theory, convective flux, stellar context for convection, semi-convection;4. energy production: nuclear binding energy, Coulomb barrier, reaction channels (PP, CNO, He, D/Li burning, s-/r-/p-processes) and rates, neutrinos

Part II. Themes, 8 wks

1. evolution of a sun-like star: Hayashi track, Li burning and Li plateau, solar neutrino problem, pressure ionization and thermal ionization, convection zone advance, rotational evolution, metal pollution by planets, the dim-sun paradox, influences on planets, RG/AGB winds and pollution of the primordial solar nebula, helioseismology2. brown dwarfs and jovian planets: D/Li burning, gravitational cooling, radiative bottle-neck, semi-convection, dust condensation and opacity (spectra), stellar irradiation and inflated hot jupiters, formation of brown dwarfs and giant planets3. high mass stars: CNO burning and core convection, Eddington luminosity and formation/mass loss of high mass stars, nucleosynthetic yield of high mass stars, rotational evolution, feedback to the galaxy, core collapse SN (SN II), pair instability, neutrino luminosity, Pop III stars, neutron star (population, rotation, magnetism), gamma-ray burst4. binary evolution: frequency of binarity, tidal synchronization and circularization, Roche lobe overflow, conservative and non-conservative mass transfer, common envelope, accretion onto degenerate objects (x-ray bursters, novaes, cataclysmic variables), merger of double degenerates, SN Ia (rates, standard candles, neucleosynthetic yield, origin)

Part III. Summary, 1 wk

leading puzzles; peculiar stars