Sun, Page 11: [Previous Page] [Next Page] [Class Home Page] Textbook pages 288 - 296

The Sun's Spectrum

The optical spectrum of a STAR is an absorption line spectrum. This is because a cooler atmosphere (gas) lies above the hotter interior.

In 1817, the German Physicist Joseph Fraunhofer discovered certain lines where missing from the Sun's spectrum. The dark bands are now referred to as 'Fraunhofer's Lines'. The full Solar Spectrum looks something like this:

The Sun does produce an emission line spectrum This is because of the energy absorbed in the upper atmosphere, which then re-releases the photons in new random directions. The Hydrogen Series of lines is particularly strong in stars (because they are mostly Hydrogen). A schematic of a Hydrogen emission spectrum is below:

When viewing the sun in H-alpha, the sun looks like THIS: To see how the Sun looked like in white light at the same time, go here For some H-alpha movies, go here.