A Son of the Rock

The sun gives out light across the visible spectrum (the colours of the rainbow) and beyond. We see the sun itself as yellow or red according to its position in the sky and what we experience as “white” light is made up of all the colours. If that light is passed through a prism or difraction grating it splits up into these colours.

What about when the sun’s rays are blocked?

Constantine Emmanouilidi caught a great picture of the sun’s spectrum split in this way but during an eclipse. This was Astronomy Picture of the Day for 15/11/13.

Thanks to Mr Emmanouilidi for permission to copy his picture.

It was through images similar to this where a line spectrum is obtained that the chemical element helium was discovered in the sun’s atmosphere before it was isolated on Earth.