Astronomy Question of the Week: What does the ?family tree? of stars look like?

Not all of the stars in the Universe are the same ? differences in brightness and colour can be recognised even with the naked eye.
In the 19th century, star spectroscopy developed into an important method of analysis in astronomy: it divides light and other electromagnetic radiation from stars according to its wavelength. For example, [...]

Full story at http://spacefellowship.com/2009/10/19/astronomy-question-of-the-week-what-does-the-family-tree-of-stars-look-like/