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Astronomy 201a (Fall 2012):
Stellar and Planetary Astrophysics
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**LECTURES AND PROBLEM SETS**

Although I won't have polished lecture notes available electronically, I will attempt to summarize the material covered in each lecture and provide links to the handouts and problem-set materials.

Tues., September 4:Introductory lecture. Overview of course syllabus, some general philosophy, and the importance of stars to astronomy. Begin discussion of kinetic and thermodynamic properties of gases.

Reading:Rose, Chapter 1. Pols, Chapter 1 (online).

Problem Set 1:due Thurs., September 13.

Handouts:

Useful physical and astronomical constants

Clayton Figure 1-1 (flowchart: the role of the star in astrophysics);

Comparative H-R Diagrams (one observational, one quasi-theoretical).

Thurs., September 6:Continue discussion of kinetic and thermodynamic properties of gases: moments of distribution functions, equilibrium statistics (M-B, B-E, F-D), and adiabatic invariants.

Reading:Collins, Chapter 1. Pols, Chapter 3. Rose, Chapter 3.

Tues., September 11:Continue discussion of kinetic and thermodynamic properties of gases: radiation pressure, electron degeneracy, ion crystallization, electron plasma screening, and pair production.

Reading:Collins, Chapter 1. Pols, Chapter 3. Rose, Chapter 3.

Handouts:

Equation of state T versus rho diagram showing many different regimes of parameter space.

Thurs., September 13:Start discussion of energy sources in stars: gravitational contraction and definition of dynamical time scale. Then introduce virial theorem and the Kelvin-Helmholtz thermal time scale. Also begin discussing nuclear energy generation via fusion in stellar cores.

Reading:Collins, Chapter 3. Pols, Chapters 2, 6.

Handouts:

Binding energy curve for all known atomic nuclei.

Problem Set 1 due.

Tues., September 18:Nuclear energy generation: derive cross sections, reaction rates, and properties of the Gamow peak. Begin discussion of important nuclear burning cycles.

Reading:Pols, Chapter 6. Collins, Chapter 3. Rose, Chapter 6.

Problem Set 2:due Thurs., September 27.

Handouts:

Energy generation rates as a function of core temperature.

Summary of main hydrogen burning reaction chains.

Clayton Figure 7-3 (chart of nuclei that participate in major burning stages)

Thurs., September 20:End discussion of nuclear energy generation: photodisintegration, neutron capture, and radioactive decay. (For context, HERE is a periodic table.) Begin talking about equations of spherical stellar structure.

Reading:Pols, Chapter 6. Collins, Chapter 3. Rose, Chapter 6.

Tues., September 25:Continue presenting equations of stellar structure. Radiation transport mechanisms: derive temperature gradients due to radiative diffusion and heat conduction. Begin mixing-length theory of convection.

Reading:Pols, Chapter 5. Collins, Chapter 4.

Handouts:

Plot of Rosseland mean opacity versus temperature and density.

Thurs., September 27:Finish discussion of mixing-length theory of convection. Begin full problem of time-steady spherically symmetric stellar interiors.

Reading:Pols, Chapter 7. Collins, Chapter 4.

Problem Set 2 due.

Tues., October 2:Stellar structure models: explore the constant-density "homology" approximation, then derive the Lane-Emden equation for polytropic equations of state.

Reading:Pols, Chapters 4 and 7. Collins, Chapters 2 and 4. Rose, Chapter 2.7-2.9.

Handouts:

Collection of mass-radius relationships for stars and planets.

Summary of properties of polytropes.

Problem Set 3:due Thurs., October 11.

Thurs., October 4:Finish discussion of polytropes and examine various example cases of polytropic indices that correspond to realistic stellar or planetary conditions. Investigate Eddington limit and Eddington's "standard" stellar model.

Reading:Same as last lecture.

Finalize project topics.

Tues., October 9:Discuss stellar rotation, oblateness, and 3D generalizations of the spherical stellar structure equations. Begin discussion of tidal deformation by a close companion.

Reading:Collins, Chapter 7. Rose, Chapter 9.3-9.4.

Handouts:

Summary plots of Roche model oblateness and von Zeipel gravity darkening.

Thurs., October 11:Finish discussion of tidal deformation and tidal heating. Begin stellar pulsation with the equations of time-dependent hydrodynamics, wave propagation in stars, and the Baker one-zone model.

Reading:Collins, Chapter 8. Rose, Chapter 8. Pols, Chapters 7.5 and 10.4.

Problem Set 4:due Tues., October 23.

Problem Set 3 due.

Tues., October 16:Conclude stellar pulsations and seismology with discussion of the full non-radial pulsation (NRP) problem.

Reading:Same as last lecture. (The NRP material will be highly reminiscent of Chapter 7.1 of my 1996 PhD Thesis.)

Thurs., October 18:Finish pulsations. Discuss star formation: ISM thermal instabilities, turbulence, and the Jeans criterion.

Reading:Collins, Chapter 5. Pols, Chapter 9.

Handouts:

ISM thermal stability diagram for star formation.

Tues., October 23:Finish star formation with a derivation of the initial mass function. Begin pre-main-sequence stellar evolution with discussion of the Hayashi track.

Reading:Collins, Chapter 5. Pols, Chapter 9.

Problem Set 4 due.

Problem Set 5:due Thurs., November 1.

Thurs., October 25:Continue pre-main-sequence evolution: Henyey track, accretion disk physics, and properties of T Tauri stars.

Reading:Collins, Chapter 5. Rose, Chapter 9.2. Pols, Chapter 9.

Tues., October 30:Finish pre-main-sequence evolution. Begin post-main-sequence stellar evolution: main sequence lifetimes, core/envelope separation.

Reading:Same as last lecture.

Handouts:

Luminosity versus time for young stars, brown dwarfs, and planets (by Adam Burrows).

Flowchart of stellar evolution stages after the main sequence.

Thurs., November 1:Continue discussion of post-main-sequence stellar evolution: mirror/bounce effect (cores collapse while envelopes expand); low-mass core cooling versus high-mass core heating.

Reading:Collins, Chapter 5. Pols, Chapters 10 and 11.

Problem Set 5 due.

Tues., November 6:Finish post-main-sequence stellar evolution. Begin discussing stellar death, supernovae, and compact remnants.

Reading:Pols, Chapters 12 and 13. Rose, Chapters 11 and 13.

Problem Set 6:due Thurs., November 15.

Thurs., November 8:Finish discussing stellar death, supernovae, and compact remnants. Begin radiative transfer and stellar atmosphere theory (partial review of Ay150).

Reading:For stellar death: same as last lecture. Radiative transfer: Collins, Chapters 9 and 10.

Tues., November 13:Continue radiative transfer and stellar atmosphere theory: the gray atmosphere, radiative equilibrium, Eddington's approximations, departures from plane-parallel geometry.

Reading:Collins, Chapters 9 and 10 (and skim chapters 11 and 12).

Thurs., November 15:Begin discussion of spectral line formation and broadening (partial review of Ay150): Non-LTE Einstein coefficients, Schuster reversing layer model of line formation.

Reading:Collins, Chapters 13 and 14.

Problem Set 6 due.

Tues., November 20:Finish discussion of spectral line formation and broadening: derivation of line profile function for various kinds of broadening mechanisms, and discussion of curve of growth.

Reading:Same as last lecture.

Handouts:

Summary plot of line broadening functions and the curve of growth.

Thurs., November 22:Thanksgiving holiday.

Tues., November 27:Discuss chromospheres and coronal heating.

Thurs., November 29:Discuss acceleration of stellar winds.

Handouts:

H-R Diagram highlighting different types of stellar mass loss.

Term Project due.

Tues., December 4:(No lecture on this day. I'll be away at a conference between December 4 and 7, but I'll try to keep up on email during that time.)

December 5-12:Reading Period.

December 13-21:Final Exam Period.

In class, we agreed onMonday, December 17, 11:00-12:30as the date and time of the final exam. I've reserved the classroom A-101 for this time.

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