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Home / Physics of Stars Problem Phillips 3.8 Solution

Physics of Stars Problem Phillips 3.8 Solution

F32AA4 The Structure of Stars

The HR Diagram

This module develops an understanding of the various physical processes involved in stars of different types and uses this to build simple mathematical models of stellar structure and evolution.

Key Objectives

  • Understand the basic properties of stars, how they are measured, and their importance in constructing models of structure and evolution.
  • Understand the importance of gravity in stellar structure, to apply Newton's laws to spherical mass configurations, and to understand and apply the concept of hydrostatic equilbrium.
  • Understand the relevant aspects of kinetic theory and apply them in the physical conditions relevant to stars
  • Understand how degeneracy pressure acts in white dwarfs and neutron stars.
  • Understand energy transport by radiation and convection, and discuss their relative importance in different types of star.
  • Understand the physical processes involved in the production of energy from nuclear reactions in stars, and understand which reactions are important in different stellar environments.
  • Be able to construct mathematical models of stars based on polytropes or other approximations and use simple models to construct scaling relationships for stars of different types.
  • Be able to give a qualitative account of stellar evolution for stars of different mass.

Course Outline

  • Basic Properties of Stars . Mass, Luminosity, Effective Temperature and Radius, the HR (Colour-Magnitude) Diagram and its importance, the basic structure of stars. [2]
  • Gravity in Stars . Interior field of a spherical distribution; gravitational collapse and dynamical timescale; pressure and hydrostatic equilibrium; inequalities for the central pressure; the virial theorem.[3]
  • Kinetic Theory in Stars . Gas pressure; the equation of state; ionization and the mean molecular weight; inequality for the central temperature; degeneracy and the conditions for its onset[3]
  • Polytropic Stellar Models . Applications to white dwarfs and neutron stars; mass-radius relations; central pressure and density. [3]
  • Energy Production and Transport . Nuclear Reactions; the p-p chain, CNO cycle & Triple-alpha process; Radiation; Opacity; Convection; Schwarzschild's criterion. [4]
  • Models of Main Sequence Stars. Proof of existence of main sequence for given homogeneous chemical composition; Mass-luminosity and mass-radius relations). [3]
  • Stellar Evolution. Descriptive account of pre- and post-main sequence stellar evolution for stars of different mass. [2]

Books

  • [PR] Prialnik, D. An Introduction to the Theory of Stellar Structure and Evolution (CUP, Cambridge, 2000).
  • [PH] Phillips, A.C. The Physics of Stars, Second Edition (John Wiley & Sons, Chichester, 1999).
  • [CO] Carroll, B.W. & Ostlie, D.A. Introduction to Modern Astrophysics (Addison-Wesley, 1996)
  • [RT] Tayler, R.J. The Stars: Their Structure and Evolution, 2nd Edition (Cambridge University Press, 1994).
The recommended text for this module is PR. PH is also good, but covers the material in a slightly different way. CO is a general course on astrophysics which covers the material for this module in a different way and does not use SI units. It is a useful source for other modules run here at Nottingham (such as Structure of Galaxies, and Cosmology) so it's worth buying if you're doing those too.RT is a nice overall introduction to the subject, but a little too descriptive for this module.

Problem Sheets and Solutions

The following files are in postscript format: they can be viewed using Ghostview (or a similar postscript viewer). Ghostview can be found under the Graphical Software section of NAL, and is available as a plug-in for web browsers. It can be downloaded here.

To download the first problem sheet click here (in postscript form).   Answers can be found  here

To download the second problem sheet click  here.  Answers can be found  here.

To download the third problem sheet click here.

To download the fourth problem sheet click  here. Answers can be found   here.

To download the fifth problem sheet click here. Answers can be found here.

To download the sixth problem sheet click here. Answers can be found here.

Lecture Notes

I aim to put here the full lecture notes during the semester. For the moment I am just putting some preliminary versions of a few chapters, which you can download for your information. They can contain errors, though, so I don't guarantee anything. At present, the texts are atill quite crude,  with several figures missing. Better versions should however be here very soon.

Basic Properties of Stars (Chapter 1)

 Gravity in Stars (Chapter 2)

Microscopic quantities in stars (Chapter 3).

Polytropes (Chapter 4)

Energy Production and Transport in Stars (Chapter 5)

 Stellar Models (Chapter 6)

The Evolution of Stars - A Schematic Picture (Chapter 7)

The Evolution of Stars - a More Detailed Picture (Chapter 8 - Part A)

The Evolution of Stars - a More Detailed Picture (Chapter 8 - Part B)

Useful Graphics and Links to Web Sites

There are many interesting astronomy and astrophysics sites on the web. I shall add some relevant ones here as the course develops but you can find many more by searching.

Gravitational Energy . From a lecture course.

Virial Theorem . Again, from a lecture course.

Movie showing binary star orbits

Movie showing evolution from Main Sequence

Hubble Space Telescope Pictures by Subject . A huge selection of images concerning various astronomical objects, including stars, nebulae and supernovae sorted by category.

Page Maintained By : Dr. Reynier Peletier

To go to Reynier Peletier's home page Click Here
Last Revision : 5 January 2003

Physics of Stars Problem Phillips 3.8 Solution

Source: http://www.astro.rug.nl/~peletier/stars_old.html