Astronomy 321

Astronomy 321: Topics in Astrophysics

Astr 321 is an introduction to stellar structure and evolution. The course will include a brief description of the observational properties of stars, followed by a detailed discussion of the equilibrium stellar structure equations and the physics appropriate to stellar structure including nuclear energy generation, the equation-of-state, opacity sources, and energy transport mechanisms. Using the basic physics of stars, we will next consider the structure and properties of Main Sequence stars using the Sun as a paradigm, the post-Main Sequence evolution of low mass and high mass stars, stellar deaths, and compact stars (white dwarfs, neutron stars, strange stars, and black holes). Time permitting, we will discuss star formation.

Instructor:

Class Hours and Room:

Office Hours:

Text:

Reading:

Grading:

Week

Reading

Topics

Homework

Due Date

1

Chapter 2: Basic Observations

Stellar Spectra: blackbody radiation and its properties, atomic structure, line spectra, spectral classification; Stellar temperatures: color temperature, effective temperature, line temperature.

Set 1

04/11/2008

2

Chapter 2: Basic Observations

Luminosities and distances; masses, binary stars, and Kepler's 3rd Law of Planetary Motion, Mass-Luminosity Relation; Hertzsprung-Russell diagram and observational scaling laws.

Set 2

04/18/2008

3

Chapter 3: Stellar Physics

Equilibrium stellar structure equations (conservation laws), equations of mass conservation (the continuity equation), equation of momentum conservation (equation of hydrostatic equilibrium); Dimensional analysis and theoretical derivations of scaling laws for L*, Tc, Pc as functions of M*.

Set 3

04/25/2008

4

Chapter 3: Stellar Physics

Virial Theorem, Stellar energy equations (relativistic vs nonrelativistic gases); Energy conservation (energy generation and heat transport), Dimensional analysis, Solar Neutrino Experiments

Set 4

05/07/2008

5

Chapter 3: Stellar Physics

Solar Neutrino experiments; Carbon-Nitrogen-Oxygen cycle; nuclear energy generation rates, Tunneling; Main Sequence Scaling Laws; Upper and Lower Main Sequence mass limits, radiation pressure, degeneracy pressure

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6

Chapter 4: Stellar Evolution and Stellar Remnants

Overview of stellar evolution, Russell-Vogt Theorem, advanced nuclear burning phases (and element production--Nucleosynthesis); Evolution of low mass stars: Main Sequence ---> Red Giant ---> Horizontal Branch ---> Asymptotic Giant Branch ---> Planetary Nebula ---> White dwarf.

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7

Chapter 4: Stellar Evolution and Stellar Remnants

Evolution of low mass stars: Main Sequence ---> Red Giant ---> Horizontal Branch ---> Asymptotic Giant Branch ---> Planetary Nebula ---> White dwarf.

Set 5

05/23/08

8

Chapter 4: Stellar Evolution and Stellar Remnants

White dwarfs: mass-radius relation, Chandraskehar mass limit; cooling of white dwarfs; cataclysmic variables (novae, recurrent novae, x-ray binaries); Type Ia Supernovae.

Set 6

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9

Chapter 4: Stellar Evolution and Stellar Remnants

Evolution of high mass stars: Main Sequence ---> Red Giant ---> Horizontal Branch ---> Asymptotic Giant Branch ---> advanced stages of nuclear burning ---> Type II Supernovae ---> neutron star or black hole.

Set 7

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10

Chapter 4: Stellar Evolution and Stellar Remnants

Type II Supernovae, SN 1987A, neutron stars (pulsars, x-ray binaries, gamma-ray bursters, merging neutron star binaries and LIGO), strange stars, and black holes.

Set 8

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Chapter 4: Stellar Evolution and Stellar Remnants

The Instability Strip and Variable Stars: in particular, RR Lyrae stars, Type I and Type II Cepheids

Set 9

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