The Sun

Discuss theory on astronomy, physics and general space science.
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CEtherington
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The Sun

Post by CEtherington » Thu Jan 24, 2019 8:36 am

We've had a question from John in Bolton.
He wants to know, "How do we know what the Sun is made of? "
Would any members like to help?
You can run with the big dogs, or sit on the porch & bark.

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rwilkinson
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Re: The Sun

Post by rwilkinson » Thu Jan 24, 2019 9:51 am

It's by analysing sunlight using a spectrograph.
Splitting the light into a continuous spectrum, we can see lots of dark lines, each of which is due to absobtion by particular elements or molecules. These can be identified by comparing with the spectra of known substances in the lab.
It's interesting to note that the element Helium was discovered by analysis of the Sun's spectrum before it was ever found on Earth.

Prof. Jim Al-Khalili's programme all about "Light" is still available on the BBC iPlayer. About 25 minutes in he explains how spectra reveal the composition of stars. https://www.bbc.co.uk/iplayer/episode/p ... rk-1-light

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