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Stars & Galaxies - PHY00076H

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  • Department: Physics
  • Module co-ordinator: Dr. Charles Barton
  • Credit value: 20 credits
  • Credit level: H
  • Academic year of delivery: 2023-24

Module summary

This module allows you to take all the physics and mathematical skills and knowledge, along with your competencies in astrophysics, that you have acquired in the previous years and apply them in a balanced and rigorous way to practical physical systems of stars and galaxies.

Related modules

 Pre-requisites:  Astrophysical Technologies and Space Science or equivalent

Module will run

Occurrence Teaching cycle
A Semester 1 2023-24

Module aims

You will take all the physics and mathematical skills and knowledge you have acquired in the previous years, along with your competencies in astrophysics, and apply them to practical physical systems - typically stars and galaxies. Your knowledge of the underlying fundamental physics, ability to create simple models and apply theories, and experience with solving quantifiable problems will be used to explore some of the most interesting aspects of stellar evolution and structure, galaxy dynamics and the interstellar medium. There is a balance between physics and astrophysics throughout this module.

Module learning outcomes

Describe in detail how matter and radiation is distributed across a galaxy, and apply physics principles to explain the evolution of stars and the phases in the interstellar medium.

Describe and quantify stellar evolution to and from the main sequence and the endpoints of stellar evolution as a function of stellar mass.

Explain and appraise the impact of stellar evolution on the interstellar medium, including the role played by radiation, winds, shocks and energetic particles.

Apply physics concepts to evaluate the interactions between radiation and the plasma, atomic molecular and dust components of interstellar medium.

Discuss and appraise the formation and evolution of galaxies and their extreme properties, including active galactic nuclei.

Module content

  • Big Bang nucleosynthesis and gravitational contraction

    • The synthesis of light elements

    • hydrostatic equilibrium of non-relativistic and ultra-relativistic particles.

  • Star Formation and the Sun

    • The Jean’s Criteria

    • contraction of a protostar

    • conditions for stardom

    • pressure, density, temperature of stars

    • solar radiation.

  • Links to radiation transport laser plasma measurements of opacities relevant to stellar physics

  • Stellar Nucleosynthesis and Stellar Life Cycles

    • Stellar mass and the extent of thermonuclear fusion

    • burning cycles

    • neutron capture

    • the rate and endpoint of stellar evolution

    • abundances of chemical elements

  • Properties of Matter within stars

    • Ideal gas law

    • density of states

    • internal energy and pressure

    • ideal classical gas

    • electrons in stars

    • degenerate electron gases

    • density-temperature diagram.

  • Properties of Radiation within stars

    • Photon gas

    • radiation pressure

    • the Saha Equation

    • ionisation in stars and stellar atmospheres

    • pair production and photodisintegration.

  • Heat transfer in stars

    • heat transfer via random motion of particles and photons

    • convection

    • temperature gradients in stars.

  • Thermonuclear fusion in stars

    • barrier penetration

    • cross sections and reaction rates

    • H burning, the p-p chain, and the CNO cycle

    • He burning

    • C production and consumption

    • advanced burning to Fe-Ni region.

  • Stellar structure

    • pressure, temperature and density inside stars

    • Modelling the Sun

    • minimum and maximum masses of stars.

  • Endpoints of stellar evolution

    • white dwarfs

    • collapse of stellar cores

    • neutron stars

    • black holes.

  • Helioseismology

    • pressure and gravity waves

    • normal modes of oscillation

    • observations of our Sun from Earth and satellite missions.

  • Our Galaxy:

    • Structure, spiral arms, rotation, mass,

    • The Interstellar Medium, Gas & Dust,

    • Thermal and Non-thermal emissions, Observational Techniques

  • Other Galaxies:

    • Classes, formation, structure and evolution

    • Active galaxies

    • Distribution and large-scale structure


Task Length % of module mark
Essay : Essay in CAP
N/A 80
Essay : Physics Practice Questions
N/A 20

Special assessment rules



Task Length % of module mark
Essay : Essay in CAP
N/A 80

Module feedback

'Feedback’ at a university level can be understood as any part of the learning process which is designed to guide your progress through your degree programme. We aim to help you reflect on your own learning and help you feel more clear about your progress through clarifying what is expected of you in both formative and summative assessments.

A comprehensive guide to feedback and to forms of feedback is available in the Guide to Assessment Standards, Marking and Feedback. This can be found at:

The School of Physics, Engineering & Technology aims to provide some form of feedback on all formative and summative assessments that are carried out during the degree programme. In general, feedback on any written work/assignments undertaken will be sufficient so as to indicate the nature of the changes needed in order to improve the work. Students are provided with their examination results within 25 working days of the end of any given examination period. The School will also endeavour to return all coursework feedback within 25 working days of the submission deadline. The School would normally expect to adhere to the times given, however, it is possible that exceptional circumstances may delay feedback. The School will endeavour to keep such delays to a minimum. Please note that any marks released are subject to ratification by the Board of Examiners and Senate. Meetings at the start/end of each semester provide you with an opportunity to discuss and reflect with your supervisor on your overall performance to date.

Our policy on how you receive feedback for formative and summative purposes is contained in our Physics at York Taught Student Handbook

Indicative reading

Phillips A C: The Physics of Stars (Wiley, 2nd Ed 1999)***

Kippenhahn R and Weigert A: Stellar Structure and Evolution (Springer-Verlag)*

Dyson J. E. & Williams D. A: The Physics of the Interstellar Medium (IOP, 1997)

Elmegreen D: Galaxies and galactic structure (Prentice Hall)

Sparke L & Gallagher J: Galaxies in the Universe (Cambridge, 2007)

Carroll & Ostlie: An Introduction to Modern Astrophysics (Pearson)**

Zeilik M & Gregory S.A.: Astronomy and astrophysics (Brooks-Cole)**

The information on this page is indicative of the module that is currently on offer. The University is constantly exploring ways to enhance and improve its degree programmes and therefore reserves the right to make variations to the content and method of delivery of modules, and to discontinue modules, if such action is reasonably considered to be necessary by the University. Where appropriate, the University will notify and consult with affected students in advance about any changes that are required in line with the University's policy on the Approval of Modifications to Existing Taught Programmes of Study.