Stellar Astrophysics

Unit Code: HET611

Credit Points: 12.5 Credit Points

> Related Course/s
> Teaching Methods
> Assessment
> Aims & Objectives
> Generic Skills Outcomes
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Related Course/s:

A unit of study in the Graduate Certificate of Science (Astronomy), Graduate Diploma of Science (Astronomy) and Master of Science (Astronomy) 

Aims & Objectives:

Aims
Following on from HET603, 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.

Teaching Methods:

Online Delivery Mode, Contact via Newsgroup and Email

Assessment:

Assessable newsgroup contributions, online tests and project. 

Generic Skills Outcomes:

Participation in HET611 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

Content:

• Classifying stars: magnitudes, colours, spectral types, luminosity classes; physical properties of stars: flux, luminosity, temperature, radius, mass; determining distances; stellar spectra; the HR diagram
• Stellar energy: gravitational contraction versus fusion, nuclear binding energy, stellar nucleosynthesis, reaction rates, PP chain, CNO cycle, triple alpha process
• Hydrostatic equilibrium and radiation pressure; equation of state; energy transport: opacity, absorption and emission mechanisms, convection; equations of stellar structure; stellar atmospheres
• Protostars: cloud collapse, Jeans criterion and fragmentation, triggered star formation, the initial mass function, evolutionary tracks and the ZAMS, T Tauri stars, protostellar jets, accretions disks, proplyds
• Binary stars: formation theories; evolution of close binaries: Roche limit and accretion disks, novae, cataclysmic variables, low mass and high mass X-ray binaries
• Main sequence stars: low mass and high mass stars, energy generation, PP chain versus CNO cycle; abundance profiles; the end of hydrogen core burning and lifetime on the MS
• Evolution off the main sequence: low mass versus high mass stars; hydrogen shell burning, red giant branch, degenerate gas pressure, asymptotic giant branch, helium flash, the horizontal branch, dredge-ups, thermal pulsing, and nucleosynthesis; planetary nebula, white dwarfs, electron degeneracy pressure, the Chandrasekhar limit
• Supernovae: type Ia and type II supernovae, light curves, explosive nucleosynthesis, supernovae remnants; galactic chemical evolution
• Neutron stars: properties, 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; Einstein’s theory of general relativity, spacetime curvature; Hawking radiation, black hole evaporation
• Pulsating stars: classed of pulsating stars and the instability strip, partial ionisation zones, opacity, thermodynamic heat engines; modelling pulsations, radial and non-radial modes, helioseismology
• Stellar clusters: types of clusters, open clusters and stellar evolution models, globular clusters and distances; colour-magnitude diagrams, metallicity, turn-off points

Textbooks: