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PX158 Astronomy

Lecturer: Dan Bayliss
Weighting 10 CATS

Astronomy is the study of everything that occurs beyond the Earth's atmosphere. The module covers the concepts and techniques that are the basis of astronomy. It investigates a diverse range of astronomical objects, ranging from planets, to stars and galaxies, to the Universe as a whole. We focus on the fundamental properties of these objects, such as their masses, sizes, distances and temperatures. We will see that understanding of what is observed requires understanding of fundamental physics, particularly in relation to gravity and light, as well as mathematics.


To describe the constituent objects of the Universe and the physics needed to estimate their distances, sizes, masses and natures. The module will show how our knowledge of the Universe beyond Earth relies upon the application physical theories and experimental techniques.


By the end of the module, students should be able to:

  • Demonstrate understanding, and make use, of concepts in astronomy, including astronomical coordinates, angles, fluxes, and magnitudes
  • Identify, describe, and demonstrate understanding of the main constituents of the Universe, including planets, stars, black holes, and galaxies
  • Describe the techniques and methods for measuring the distances and masses of stars and galaxies


Description of the main constituents of the Universe with typical sizes, masses and distances covering: planets, stars, blackholes, and galaxies.

Angles, distances & sizes: angular size and the small-angle approximation; trigonometric parallax; simple astronomical telescopes, spectrographs, and detectors.

Masses: the Doppler effect and the measurement of speed from spectra; the use of speeds and sizes to derive masses in the Solar System, binary stars, star clusters and galaxies.

Physical properties of stars: stellar temperatures; spectra and elemental compositions. Physical conditions within stars.

Galaxies: the Milky Way; galaxy types, galaxy evolution.

The Universe: Hubble's discovery of the expansion of the Universe; implication of a finite age; the Big Bang, the Cosmic Microwave Background; the composition of the Universe.

Commitment: 30 Lectures + 5 problems classes

Assessment: 2 hour examination

Recommended Texts: Marc Kutner, Astronomy: a Physical perspective , CUP