Syllabus

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. 

Instructor: Yanqin Wu, MP 1210, wu@astro

Lectures: Wed. 1:30-3:00PM (AB114), Friday 12:30-2:00PM (AB 114/113)

Office Hour: drop by my office

Course Website:    http://www.astro.utoronto.ca/~wu/AST1410

Textbook: Hansen, Kawaler & Trimble, stellar interiors (2nd edition, 2004, Springer)

Optional Readings:


Evaluation:
Problem sets (30%), Oral Presentation (20%), Computer project for stellar evolution (20%), Final exam (20%)

There will be 3 problem sets due two weeks after posting. We will run presentations throughout the term. Each student will present two short (8 min. + 7 min. discussions/questions) and one long (20 min. + 5 min. discussions/questions) talks. The short one will be to explain an important concept in stellar astrophysics, and the long one will be on an advanced topic (list of topics to come). Each student will be required to construct a simple stellar model, and analyse stellar evolution results from the MESA code. The final exam will be a take-home exam of 3 hours duration (no references may be consulted, however).

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 evolution

2. 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, helioseismology

2. 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 planets

3. 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 burst

4. 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