Astro 580: Stellar Structure and Evolution
Spring 2004

Time and Room: Instructor: Dr. Steven Kawaler

Books: Required

All texts should be available (eventually) from the University Bookstore, or through online bookstores. Though the second and third are somewhat dated, they contain very clear presentations of the basic physics of stars. They are reasonably priced, and belong on the book shelf of all astronomers.

Books: Recommended

PRELIM. EXAMS: There will be two midterm exams, each worth 20% towards your total grade. All exams will be open-book or take-home, at arranged times outside of class.

FINAL EXAM: The final exam will be worth 30% of your total grade. It will be a 48 hour take-home exam (no, it won't take 48 hours to do, but is due 48 hours after being handed out).

PROBLEM SETS: Approximately 5 problem sets will be assigned this term. You may (and are encouraged to) work together on these problems. However, each student is expected to turn in his/her own paper with his/her own work. Identical answers to essay-type questions, or to interpretation of numerical results, will be severely frowned upon. Problems will frequently require computer solutions (just like in real life). Therefore you are all strongly encouraged to have a Unix/Linux computer available; if you don't I can help set you up on a lab computer. Taken together, the problem sets account for 20% of your total grade.

COMPUTATIONS: Stellar evolution "theory" is really numerical experimentation using more-or-less standard modeling codes. With the abundance of computing equipment available to you, we can make extensive use of several stellar strucure and evolution codes that run on machines ranging from Vincent systems to PCs and Macs. Expect to be running these codes with an eye towards solving real problems in addition to supporting analytical exercises. In addition, some of the problem sets will require numerical solutions using tools that you will have to develop on your own... either by writing Fortran or C code, or by intelligent use of packages such as Mathematica.

PRESENTATION: By the end of this course, you will be expected to have the ability to read, critically and intelligently, any Astrophysical Journal paper on stellar structure and evolution. To demonstrate this, we will have a miniature Stellar Symposium. Each student will be required to present a 40 minute talk (30 minute presentation, with 10 minutes for questions) about a paper that has appeared in the literature within the past two years. These talks will be open to the class and any interested members of the Physics and Astronomy department. Refreshments will be provided by your instructor. Papers to be presented will require approval from the instructor one month prior to the Symposium. The presentation (and a general assessment of your class participation) will account for the remaining 10% of your total grade.

COURSE OUTLINE: TENTATIVE!! Note that we have only 15 weeks to cover this enormous field! Thus the following breakdown in timing is only preliminary. We must reserve some flexibility to ensure that we cover, or at least touch upon, as many of these important topics as possible.

  1. Preliminaries (1.5 weeks)
    1. Mechanical structure: time scales, order-of-magnitude estimates
    2. Thermal structure: energy transport, generation, time scales
    3. The Equations of Stellar Structure
    4. The overall problem: simple solutions and homology
  2. Stellar Evolutionary Stages: An Overview (2 weeks)
    1. Pre-main sequence and star formation
    2. Main sequence systematics
    3. Late stages: low, intermediate, and high masses
    4. Interacting binary stars
    5. Pulsating variable stars
    6. Supernovae
  3. Equation of State of Stellar Material (1 week)
    1. Basic thermodynamics
    2. Ideal gas
    3. Ionization and nonideal effects
    4. Degeneracy and partial degeneracy
    5. non-ideal effects
  4. Energy Transport in Stellar Interiors (2 weeks)
    1. Radiative transport in the diffusion approximation
    2. Opacity
    3. Conduction by degenerate electrons
    4. Convection and the mixing length kludge
    5. Semiconvection
    6. Realistic convection models
  5. Stellar Energy Sources (2 weeks)
    1. Energy from the gravitational field
    2. Nuclear reactions: general background
    3. Hydrogen burning: the p-p chain and neutrinos
    4. Electron screening
    5. The CNO cycles
    6. Equilibrium burning
    7. Helium burning via the triple-a process
    8. Heavier species: the s- and r- processes
  6. Stellar Models (1 week)
    1. The differential equations
    2. The Vogt Russell theorem
    3. Simple solutions: numerical techniques and polytropes
    4. Real models: structure and evolution
  7. The Sun: A Stellar Prototype (0.67 week)
    1. ZAMS structure
    2. Hydrogen depletion
    3. The Sun today: neutrinos
    4. Solar seismology
    5. The future of the Sun
  8. Late Stages of Evolution (1.33 weeks)
    1. The helium flash and horizontal branch stars
    2. AGB structures: thermal instabilities, mass loss, and s-processing
    3. White dwarfs
    4. Supernovae
    5. Neutron stars and pulsars
  9. Stellar Pulsation (1 week)
    1. Theory: radial pulsation
    2. Driving and damping of pulsations
    3. Radial pulsators: Cepheids, RR Lyra stars, and Miras
    4. Theory: nonradial pulsation
    5. Nonradial pulsators: the Sun, Ap stars, and white dwarfs
    6. Stellar Seismology
  10. Current Topics in Stellar Evolution ... as time permits (min. 1 week)
    1. Convective overshoot
    2. Age determinations
    3. Trace elements, anomalous mixing, and primordial nucleosynthesis
    4. Rotational circulation/evolution
    5. Diffusion