The March second edition of New Scientist reports on the nature of 'Mira-like' variable stars.
This phenomenon can be observed with home-made star spectroscopes. Here is such a spectroscope that is designed to be fitted onto a low power eyepiece for 6 inch f/5 telescope:
And here is a photograph of the spectrum of a red giant star taken with the instrument described above. Note the dark titanium oxide bands that absorb a large part of the light:
[Macro error: Can't evaluate the expression because the name "trackbackLink" hasn't been defined.]
