AST80016 (formerly HET611) Stellar Astrophysics

Course/s with Unit:
A unit of study in the Graduate Certificate of Science (Astronomy), Graduate Diploma of Science (Astronomy) and Master of Science (Astronomy).

Credit Points:
12.5 Credit Points

Duration:
One semester

Contact Hours:
Equivalent to 60 hours

Campus:
Off-campus

Prerequisites:
AST80004 Exploring Stars and the Milky Way and introductory tertiary-level mathematics & physics, or equivalent.

Corequisites:
Nil.

Learning and Teaching Structure:
Online delivery mode, contact via newsgroups & email.

Assessment:
Assessable newsgroup contributions (30%), online tests (20%) and project (50%).

Aims:
Following on from AST80004, this Unit aims to cover the physical processes underlying stellar properties and the principles behind models of stellar evolution.

Objectives:
After successfully completing this Unit, students should be able to:

  • understand the classification schemes of stars, their physical parameters and the importance of the HR diagram;
  • understand the properties and processes of stellar interiors and stellar atmospheres;
  • understand the mechanism of star formation and the evolution of stars from the main sequence through to the RGB and AGB phase;
  • have a working knowledge of the processes and properties of high mass stellar remnants, including supernovae, planetary nebulae, white dwarfs, neutron stars and black holes;
  • solve mathematical problems related to the physical processes that underlie stellar properties and evolution;
  • discuss these stellar astrophysical concepts in a non-technical manner understandable to the general public; and
  • research an astronomy topic in depth, using dependable sources of astronomical information on the internet and refereed journal articles.

Key Generic Skills:
Participation in AST80016 Stellar Astrophysics will help students develop the attributes that are considered desirable in a Swinburne graduate including the following generic skills:

  • analysis skills
  • problem solving skills
  • communications skills

Content:

  • Classifying stars: magnitudes, colours, spectral types; physical properties: flux, luminosity, temperature, radius, mass; distances; stellar spectra; the HR diagram
  • Stellar energy: gravitational contraction versus fusion, stellar nucleosynthesis, reaction rates, PP chain, CNO cycle, triple alpha process
  • Hydrostatic equilibrium and radiation pressure; equation of state; energy transport: opacity, convection; equations of stellar structure; stellar atmospheres
  • Protostars: cloud collapse, Jeans criterion and fragmentation, initial mass function, evolutionary tracks and ZAMS, T Tauri stars, protostellar jets, accretions disks, proplyds
  • Main sequence stars: low mass and high mass stars, energy generation, PP chain versus CNO cycle; end of hydrogen core burning and lifetime on the MS
  • Evolution off the main sequence: low mass versus high mass stars; red giant branch, degenerate gas pressure, AGB, helium flash, horizontal branch, dredge-ups and thermal pulsing; planetary nebula, white dwarfs, electron degeneracy, Chandrasekhar limit
  • Supernovae: type Ia and type II supernovae, light curves, explosive nucleosynthesis, supernovae remnants
  • Neutron stars: neutron degeneracy, rotation, magnetic fields, pulsar lighthouse model, synchrotron radiation, spin-down and pulsar lifetimes, dispersion and distance measures, millisecond pulsars
  • Stellar mass black holes: formation mechanisms, escape velocity, Schwarzschild radius, event horizon, spaghettification; spacetime curvature; Hawking radiation, black hole evaporation
  • Pulsating stars: the instability strip, partial ionisation zones, thermodynamic heat engines; modelling pulsations, radial and non-radial modes, helioseismology
  • Binary stars: formation theories; evolution of close binaries: Roche limit and accretion disks, novae, cataclysmic variables, low mass and high mass X-ray binaries
  • Stellar clusters: types of clusters, open clusters and stellar evolution models, globular clusters and distances; colour-magnitude diagrams, metallicity, turn-off points

Prescribed Textbook & Reading Materials:
For information about the textbook, follow this link.

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