Astro 465: Stellar Astrophysics II (winter 2012)
This page will be updated. Information here can be not final, the final syllabus will be given in class on Jan 9th.
- In this course we aim to cover the essential physics of the internal structure of stars -
the basic equations of stellar structure, opacity, and nuclear reactions. We will discuss at a semi-quantitative level
how stars evolve, starting from prior the main sequence and to the ends of their life. We also will compute and analyze stellar models using realistic stellar evolution code.
- Literature:
Useful/further reading:
- `` An Introduction to the Theory of Stellar Structure and Evolution'' by D.Prialnik.
- `` Stellar Structure and Evolution'' by R. Kippenhahn and A.Weigert
- `` Evolutionary Processes in Binary and Multiple Stars'' by P. Eggleton (available online in UofA library)
- `` Principles of Stellar Evolution and Nucleosynthesis'' by D. Clayton
- Marking scheme
- Problem solving homeworks: 30%. Due Jan 30, Feb 8, Feb 17, Mar 14, Mar 28, Apr 11
- Computational HWs: 40%. Due March 2, Apr 4
- Take home final exam: 30%. TBA
- Full syllabus
Special note for 3d year undergraduate students: please think twice before you enroll in this course. The course requires advanced ability to set up and solve problems. Students are usually trained in this by the end of their 4th year, 3d year students have showed before bad performance. This is not about the formal list of pre-requisite courses, its about your overal training as a physicist and your expereince with solving complex physical problems. This is not a pretty-astro-pictures based course.
Lecture notes are not guaranteed. I will attempt to provide most of them onine here,
but you should make a fair effort to make your own notes
or cooperate with classmates in case you are absent.
I will be not giving out any notes in addition to the posted below.
This class works in CGS units ONLY. No SI units homeworks will be accepted.
- Physical and Astronomical constants (CGS units)
Preliminaries
- Lecture 1: Introduction. Mass equation. Gravitational potential.
- Lecture 2: Hydrostatic equilbrium and its consequences. Rotating Star.
- Lecture 3: Gravitational energy. HE as stability point. Two derivations of the virial theorem.
- Lecture 4: Consequencies of the virial theorem. Timescales. Mean molecular weight.
- Lecture 5: Energy and energy transport equations. Homology.
EOS
- Lecture 6: LTE. Distribution function. Chemical potential. Photon gas . The add-on: geometrical factor for pressure
- Lecture 7: Ideal gas. Saha equation and its limitations. Pair production.
- Lecture 8: Degenerate EOS: complete degeneracy, finite temperature effect, partial degeneracy. Neutronization.
- Lecture 9: Specific heat and adiabatic exponents
Radiative and conductive transfer
- Lecture 10: Intensity, flux, pressure and transfer equation, TrEq in empty space
- Lecture 11: Formal solution. Source function. Strict and non strict LTE.
- Lecture 12: Diffusion approximation. Mean opacities. Nabla. Photosphere (tau, temperature, pressure).
- Lecture 13: Photosphere (density, size). Eddington limit. Supereddington accretion.
- Lecture 14: Supereddington luminosity. Conductivity. Thermal adjustment time.
- Lecture 15: Opacities
Instabilities and convective transport
- Lecture 16: Dynamical instability, Ledoux and Schwarzschild criterions. Oscillations (Brunt-Vasala frequency). Vibrational instability.
- Lecture 17: Thermal adjustment time of a convective element. Secular (thermal) instability. Mixing length theory.
Nuclear reactions in stars
- Lecture 18: Chemical composition change, binding energy, reaction rates.
- Lecture 19: Cross-section: Non-resonant reactions, astrophysical factor, tunnel effect, Gamow peak. Weak interactions, neutron captures. The add-on:
Zeldovich approximation for tunneling probability.
- Lecture 20: S-process(classic & branching), r-process, rp-process & p-process. PP-reaction.
- Lecture 21: PP-chain detailed kinematics.
- Lecture 22: PP-chain energy production. CN, CNO & hot CNO cycles. He burning.
- Lecture 23: Advanced burning.
Stellar Modelling
- Lecture 23: What is stellar modelling. Set of differential equations. Initial conditions.
- Lecture 24: Central boundary conditions. Surface boundary conditions and their effect on the envelope. Polytropes.
- Lecture 25: Polytropes continued. Numerical methods to obtain stellar models: shooting, Shwartzchild, Heney etc
Single stars
- Lecture 26: Star formation, initial stages: jeans criterion for GMC initial collapse, further fragmentation
- Lecture 27: Pre-MS star: 6 stages, Hayashi line, pre-MS evolution. ZAMS. (Onno's notes 9.1-9.2 beofre 9.2.1) Slides
- Lecture 28: ZAMS (central condition, convective zones). MS evolution. Post-MS core and Schonberg-Chandraskehar limit. Mirror principle. (Onno's notes 9.2.1-9.3.2, 9.3.4, 10.1) Slides
- Lecture 29: Stellar stability: homologous contraction, dynamical stability, thermal stability (thermostat, nuclear runaway, thin shell burning)
- Lecture 30: Hydrogen shell burning. He core burning -- He flash. (Onno's notes 10.1-10.3.2) Slides
- Lecture 31: Horizontal branch. AGB. WDs cooling. (Onno's notes 10.3.2-11) Slides
- Lecture 32: Massive stars: end of life. Core-collapse SN: triggers, energetics, neutrino, SASI. (also Onno's notes 12-13) Slides
- Lecture 33: Remnants masses after core-collapse SN. Ia SN. Slides
Binary stars
- Lecture 33: Roche Lobe Slides
- Lecture 34: Mass transfer rate. Angular momentum. Mass-radius exponents Slides and notes
- Lecture 35: Stability of MT. Common envelope. Slides
- Lecture 36: SN in binaries. HMXBs & LMXBs. Slides
- Lecture 37: Testing binary evolution. Where is it important? Slides
Due to new copyright changes from Jan 2011, the access to the lecture notes is now restricted. Enrolled students can obtain the password from me. Please consider to protest new policies and tariff by Access Copyright.
Full manual to use ev: manual