The Open University since 2006
Alternatively you can skip the navigation by pressing 'Enter'.
Genius of the Modern World: NietzscheFriday, 24th June 2016 01:05 - BBC Radio 4 BBC4 SignedBettany Hughes takes us on an exploration of Friedrich Nietzsche's life and works. Read more: Genius of the Modern World: Nietzsche
The Big C & Me: Episode 2Friday, 24th June 2016 01:05 - BBC Two
Genius of the Modern World: NietzscheFriday, 24th June 2016 02:40 - BBC Four
Thinking Allowed 2016: A special programme on Pierre BourdieuMonday, 27th June 2016 00:15 - BBC Radio 4
The Big C & Me: Episode 2Available until Sunday, 24th July 2016 02:05In the second episode of The Big C & Me we meet an 83 year old with pancreatic cancer, a nine year old whose... Read more: The Big C & Me: Episode 2
The Big C & Me: Episode 3Available until Friday, 22nd July 2016 23:55
Thinking Allowed 2016: A special programme on Pierre BourdieuAvailable for over a year
All in the Mind - Summer 2016: Care farming; All in the Mind Awards; Turn-taking in conversationAvailable for over a year
Stonehenge before the First World WarIn this extract from Afoot In England, the naturalist and author William Henry Hudson despairs of... Read more: Stonehenge before the First World War
City in The SkyThis three-part OU/BBC co-production on BBC Two investigates the 'City in the Sky'. You... Read more: City in The Sky
Grammar mattersGrammar matters because, combined with vocabulary choice, it is our main way of making meaning.... Try: Grammar matters now
Introduction to cyber securityThis free course, Introduction to cyber security, will help you to understand online security and... Try: Introduction to cyber security now
The Sun dominates our lives by defining our day, but how much do you know and understand about it? This free course will help you to explore the workings of the brightest star in our universe looking at its structure and the main processes taking place within it. You will also examine the phenomenon of sun spots.
After studying this course, you should be able to:
- demonstrate knowledge of the electromagnetic spectrum and how it is used to infer properties of sources of radiation
- demonstrate knowledge of the range of sizes, distances and motions of objects in the Universe and how they can be measured
- demonstrate knowledge of the structure of, and the main processes operating in, the Sun
- comprehend concepts lying well outside everyday experience, including those that involve very large and very small distances, times, temperatures and energies, and those that are non-intuitive.
- Current section: Introduction
- Learning outcomes
- 1 Observing the Sun
- 2 Inside the Sun
- 3 Measuring the Sun
- 4 course summary
- 2.6 End-of-course questions
- Keep on learning
Study this free course
Enrol to access the full course, get recognition for the skills you learn, track your progress and on completion gain a statement of participation to demonstrate your learning to others. Make your learning visible!
For astronomers, the Sun is fascinating because it is our nearest star. By studying the Sun, they can gain an insight into the workings of the other millions of stars that are visible in the night sky. Learning that the Sun is a star can be a little surprising. After all, the Sun is a brightly glowing, yellow object - so bright that it is dangerous to look at it directly, and so hot that we can feel its radiation warming the whole Earth. Stars, on the other hand, are mere silvery pinpoints of light that are visible only against the darkness of the night sky and with no discernible heating effect on Earth. How can they possibly be the same sort of object? The key to the answer lies in their distances.
In astronomical terms, the Sun is relatively close, being only about 150 million kilometres (93 million miles) from Earth. The stars that are visible at night are much further away: the nearest is about 40 million million kilometres from Earth, and most are much more distant than that. Imagine looking at a glowing light bulb first from very close up and then from a much greater distance. Close up, you would see the shape of the bulb but, from far away, it would be just a point of light.
This OpenLearn course provides a sample of level 1 study in
This free course includes adapted extracts from an Open University course which is no longer available to new students. If you found this interesting you could explore more free Physics and Astronomy courses or view the range of currently available OU Physics and Astronomy courses.
Copyright & revisions
Originally published: Tuesday, 22nd March 2016
Last updated on: Tuesday, 22nd March 2016
- Creative-Commons: The Open University is proud to release this free course under a Creative Commons licence. However, any third-party materials featured within it are used with permission and are not ours to give away. These materials are not subject to the Creative Commons licence. See terms and conditions. Full details can be found in the Acknowledgements and our FAQs section.
- This site has Copy Reuse Tracking enabled - see our FAQs for more information.
If you enjoyed this, why not follow a feed to find out when we have new things like it? Choose an RSS feed from the list below. (Don't know what to do with RSS feeds?)
Remember, you can also make your own, personal feed by combining tags from around OpenLearn.
- Latest OpenLearn pages
- Latest pages from OpenLearn - Physics and Astronomy
- Latest pages tagged - sun
- Latest pages tagged - universe
- Latest pages tagged - astronomy
- Latest pages tagged - memory-work
- Latest pages tagged - Fermanagh
- Latest pages tagged - listing
- Latest pages tagged - economic decline
- Latest pages tagged - wavelength
- Latest pages tagged - radiation
- Latest comments on this page
All our alternative formats are free for you to download, for more information about the different formats we offer please see our FAQs. The most frequently used are Word (for accessibility), PDF (for print) and ePub and Kindle to download to eReaders*.
- Word (1.6 MB)
- PDF (2.4 MB)
- ePub 3.0 (1.1 MB)
- ePub 2.0 (1.1 MB)
- Kindle (524 KB)
- RSS (174 KB)
- HTML (1021 KB)
- SCORM (1020 KB)
- OUXML Package (23 KB)
- OUXML File (73 KB)
- IMS Common cartridge
*Please note you will need an ePub and Mobi reader for these formats.