How Do Astronomers Determine The Age Of Stars?

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An instructional video from Science News tells how astronomers measure the age of a star. At the opening, science writer Lisa Grossman describes the problem faced by astronomers by remarking "stars don't exactly come with a birth certificate."

The video describes three strategies - Hertzspring-Russell Diagrams, rotation rates and asteroseismology - in a 6m 13s video.

In an accompanying column, Lisa Grossman and Helen Thompson have written an article which describes the "one variable scientists haven't quite cracked yet...time." The authors continue with this jarring comment by astronomer David Soderblom (Space Telescope Science Institute). "The sun is the only star we know the age of. Everything else is bootstrapped up from there."

Grossman and Thompson discuss the three methods and close by writing a teasing bit about the importance of this question of the star ages.

"Aside from curiosity about the stars in our own back yard, star ages have implications, beyond our own solar system, from planet formation to galaxy evolution--and even the search for extraterrestrial life.

"One of these days -- it'll probably be a while -- somebody's going to claim they see signs of life on a planet around another star. The first question people will ask is, 'How old is that star?'' Soderblom says. "That's going to be a tough question to answer."