This module covers fundamental astronomy with a modern observational approach. It encompasses two broad themes of ‘Stars and Galaxies’ and ‘Multiwavelength Astronomy’. Starting from cosmic length scales, learn how astronomers measure the Universe – through spectroscopy, imaging and time-variability. You’ll learn about the constituents of stars and galaxies and study their formation, evolution and rebirth through energetic processes. To finish, revisit the Universe from the perspective of cosmic time scales. Throughout, alongside astronomy, you’ll develop your computing, maths and physics skills.
First, you’ll examine some astronomy fundamentals. You’ll learn how modern astronomers measure the universe, using spectroscopy, imaging, and time-variability as observational tools.
Topic 1: Cosmic length scales
Starting with the sizes of things, this topic explains astrometry – how we measure the positions of astronomical objects. Then, photometry – how we measure the brightness of such objects. Eventually, we’ll combine both concepts to see how to measure distances in the Universe.
Topic 2: The spectral Universe
You’ll begin by understanding how continuum emission or black body radiation enables astronomers to determine stellar temperatures, radii and luminosities. And learn about energetic processes in evolving galaxies. You’ll move on to understand absorption and emission spectroscopy, particularly how astronomers use stellar spectroscopy to classify stars. Leading to the Hertzsprung–Russell diagram, a vital tool for understanding stars and stellar evolution. Finally, you’ll see how astronomers can exploit spectroscopy to examine how astronomical objects move through space relative to each other. And to look at motions within objects, focusing on the interior of stars, the rotation of a spiral galaxy, or gas turbulence in molecular clouds.
Topic 3: Mapping and classifying the Universe
You’ll exploit the multiwavelength view modern astronomy has of stars and galaxies. You’ll reach beyond pretty pictures to learn how we can quantitatively describe astronomical objects using image measurements. See how we construct all-sky images from detailed telescopic surveys. And build a systematic understanding of the constituents of a galaxy, and where in a galaxy we find them. But we know we cannot see all the Universe, even with electromagnetic images – by the end of Topic 3, you’ll understand how we hunt for dark matter and black holes.
After you have learned the astronomy essentials, topics 4–6 focus on how we use mapping, imaging, and spectroscopy tools to reveal the lifecycles of stars and galaxies.
Topic 4: Birth and life
This topic concentrates on how the action of a single force – gravity – can generate structure on all scales. From star formation, through stellar orbits, and onwards in scale, to galaxies and even the vast web-like structures that interconnect galaxies themselves. You’ll learn more about stars by studying the nearest star to us, the Sun. And understand the nuclear processes that fuel all stars at their core.
Topic 5: Evolution and death
This topic highlights what happens to nuclear processes in the final stages of stellar lifecycles. And the interplay between the lives of individual stars and the evolution of populations of stars within galaxies. You’ll see how the initial mass of a star plays a profound role in its eventual fate. Discover supernovae explosions, the formation of white dwarfs, neutron stars and red giants. Revise the Hertzsprung–Russell diagram and trace the evolutionary track of stars. Delving into stellar archaeology, you’ll see how stellar populations reveal how galaxies change with time. And see how the abundance of chemical elements is linked to star-formation histories.
Topic 6: Extreme Universe
By ‘extreme Universe’, we mean extremely dense or hot environments or extremely high gravitational or magnetic fields. This leads to some of the most extreme events in our Universe: from the impact of supermassive black holes that power active galaxies to binary star systems to pulsars. You’ll explore jets, outbursts and accretion processes. The topic finishes by describing the first detections of gravitational waves from merging pairs of black holes and neutron stars. And the emergence of multi-messenger astronomy – where gravitational and electromagnetic detections of astrophysical events are combined.
Topic 7: Cosmic timescales
Finally, in Topic 7 we synergise everything you’ve learned in S284 – looking from the perspective of cosmic timescales, rather than cosmic length scales. You’ll see how time-variability and time-domain astronomy are as crucial in understanding astrophysical processes as length scales and measurement techniques. You’ll identify how the Universe has evolved to its current state, and how it will evolve in the future. Having seen the importance of large-scale observational facilities to modern astronomy and the need for multiwavelength and even multi-messenger telescopes, we close by considering the impact of modern astronomy on the world at large. Whilst our quest for knowledge is unabated, what impact can the cost, building and situation of international observatories have on the local environment, customs or economy? What kinds of responsibilities must astronomers consider in their quest for ‘eyes on the Universe’?
There are no formal entry requirements for this module.
At The Open University, we believe education should be open to all, so we provide high-quality university education to anyone who wishes to realise their ambitions and fulfil their potential.
Even though there are no entry requirements, you’ll need appropriate knowledge of physical sciences obtained through:
Are you ready for S284?
We recommend that you’ve completed:
Or have:
You’ll get help and support from an assigned tutor throughout your module.
They’ll help by:
Online tutorials run throughout the module. While they’re not compulsory, we strongly encourage you to participate. Where possible, we’ll make recordings available.
Course work includes:
You'll submit one TMA a month. The TMAs are shorter than those on other modules; you'll typically complete part of them by simply working through the study materials. Each TMA will take you up to three hours, and is worth 8% of your overall assessment score.
There is also an exam. You’ll take it in two parts, one in January (study week 14) and one in May (study week 31). The first part is worth 12% of your overall assessment score, and the second 40%. You must attempt at least one part of the exam.
You’ll have access to a module website, which includes:
Additionally, the website includes:
We also provide physical:
The OU strives to make all aspects of study accessible to everyone, and this Accessibility Statement outlines what studying S284 involves. You should use this information to inform your study preparations and any discussions with us about how we can meet your needs.
To find out more about what kind of support and adjustments might be available, contact us or visit our Disability support website.
Astronomy (S284) starts once a year – in October.
It will next start in October 2026.
We expect it to start for the last time in October 2028.
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