• Tuesday, Thursday: 2:10-3:30; 45 Physics
  Please note that I will need to be away for a few class periods this term. To make up time, we will occasionally run long (i.e. to 4PM at the latest). I'll let you know in advance when this will happen.

• Office: A323 Zaffarano, Lab: A529 Zaffarano
  
• Office Hours: whenever you need me
  
• Telephone: 294-9728 (office), 294-1150 (lab), 292-6060 (home; not after 10pm, please)
• e-mail: sdk@iastate.edu

Books: Required

• Stellar Interiors: Physical Principles, Structure and Evolution
  C. Hansen, S. Kawaler, & V. Trimble (New York: Springer) 2004.
  Note: This is the main book for this course. As of 1/9/09 it had not yet appeared in the bookstore I can make a CD-Rom with PDF copies of the final proofs of the book for you if you would like - just ask. When the bookstore receives the print versions, please do get the book!

  The first edition (1994) may be available at reduced price somewhere, but the new edition is sufficiently different and updated that you should use the new one.

• Introduction to Stellar Astrophysics, Volume 2: Stellar Atmospheres
  Erika Bohm-Vitense (Cambridge, Cambridge University Press)
  Not needed until last part of the course, but please do get it as soon as you can. This brief book contains a nice overview of the input physics and techniques used in stellar spectral analysis.

Books: Recommended

• Stellar Structure and Evolution
  R. Kippenhahn and A. Weigert (Berlin: Springer) 1990
• Structure and Evolution of the Stars
  M. Schwarzschild, (New York: Dover) 1958, 1965
  NOTE: This book is now (unfortunately) out-of-print. I have been able to find a few used copies (ain't the Internet wonderful...). So if you would like a copy, please let me know. They will cost between $10 and $15. No, I'm not making a profit on this one, either.
• Principles of Stellar Evolution and Nucleosynthesis
  D. Clayton, (Chicago: Univ. of Chicago) 1968, 1984

• Principles of Stellar Structure
  J. P. Cox and R. T. Giuli (New York: Gordon and Breach) 1968 Nnote: if you find a first-edition copy of this huge two volume set, I will be impressed! A reprinted version is available (edited by A. Weiss) and a good value.
• Black Holes, White Dwarfs, and Neutron Stars
  S. Shapiro and S. Teukolsky (New York: Wiley) 1983
• The Internal Constitution of the Stars
  A. Eddington (Cambridge: Cambridge Univ.) 1926, 1988
• Theory of Stellar Pulsation
  J. P. Cox (Princeton: Princeton Univ.) 1980

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 and stellar atmosphere "theory" is mostly 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, evolution, and atmosphere codes that run on readily available (Linux 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 your own code (Fortran, C, C++, python, whatever), or by intelligent use of packages such as Mathematica.

PRESENTATION / PROJECT 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. 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 four years.

This will be unlike the Astro Seminar, in that you will need to do a quantitative exploration of the paper's topic. That is, you will need to reproduce a key element of the paper's research with your own computation, or test the paper's conclusion with a new calculation or other piece of quasi-original research.

I will have more to say about the Project early in the course, including a list of recommended papers for you to analyze. As this will take some time to prepare, I will expect all students to have chosen their paper by mid-February. Of course, I will do all I can to help (including providing relevant computer codes if available), and you will be encouraged to contact the author(s) of the chosen paper for suggestions..

The talks will be open to the class and any interested members of the Physics and Astronomy department. Refreshments may be provided by your instructor. The presentation (and a general assessment of your class participation) will account for the remaining 10% of your total grade.

1. Preliminaries (1.5 weeks)
   • Observational motivation
   • Mechanical structure: time scales, order-of-magnitude estimates
   • Thermal structure: energy transport, generation, time scales
   • The Equations of Stellar Structure
   • The overall problem: simple solutions and homology
2. Equation of State of Stellar Material (1 week)
   • Basic thermodynamics
   • Ideal gas
   • Ionization and nonideal effects
   • Degeneracy and partial degeneracy
   • non-ideal effects
3. Energy Transport in Stellar Interiors (1 week)
   • Radiative transport in the diffusion approximation
   • Opacity
   • Conduction by degenerate electrons
   • Convection and the mixing length kludge
   • Semiconvection and convective overshoot
   • Realistic convection models
4. Stellar Energy Sources (1 week)
   • Energy from the gravitational field
   • Nuclear reactions: general background
   • Hydrogen burning: the p-p chain and neutrinos
   • Electron screening
   • The CNO cycles
   • Equilibrium burning
   • Helium burning via the triple-a process
   • Heavier species: the s- and r- processes
5. Stellar Models (1 week)
   • The differential equations
   • The Vogt Russell theorem
   • Simple solutions: numerical techniques and polytropes
   • Real models: structure and evolution
6. Stellar Evolutionary Stages: An Overview (1.5 weeks)
   • Pre-main sequence and star formation
   • Main sequence systematics
   • Late stages: low, intermediate, and high masses
   • Interacting binary stars
   • Pulsating variable stars
   • Supernovae
7. The Sun: A Stellar Prototype (0.5 week)
   • ZAMS structure
   • Hydrogen depletion
   • The Sun today: neutrinos
   • Solar seismology
   • The future of the Sun
8. Stellar Atmospheres and Spectra (3 weeks)
   • the Transfer Equation
   • line and continuum processes
   • opacity sources in LTE
   • line profiles - broadening mechanisms
   • the Curve of Growth
   • non-LTE and statistical equilibrium
   • modern stellar atmosphere simulation codes
   • interpretation of stellar spectra: T, P, abundances

   if time...

9. Late Stages of Evolution (1 week)
   • The helium flash and horizontal branch stars
   • AGB structures: thermal instabilities, mass loss, and s-processing
   • White dwarfs
   • Supernovae
   • Neutron stars and pulsars
10. Stellar Pulsation (1 week)
    • Theory: radial pulsation
    • Driving and damping of pulsations
    • Radial pulsators: Cepheids, RR Lyra stars, and Miras
    • Theory: nonradial pulsation
    • Nonradial pulsators: the Sun, Ap stars, and white dwarfs
    • Stellar Seismology