A Star's Age

                How do we determine the age of a star? Obviously, stars don’t have birthdays like we do, but their spin can tell us all we need to know to determine their age.

A technique called gyrochronology is used to calculate the age of a star. It utilizes a known age of a cluster of stars and its spin rate to determine the age of an isolated star. To measure the spin, astronomers look for changes in the brightness of the star, caused by dark spots, and determining the time it takes for that spot to reappear. Once that rotation period is known, it is used to determine its age by means of a mathematical formula of that only depends on the period (time) and the mass (or color) of the star.

This method was instrument in determining more precise ages of stars.

Works Cited:

Nasa:            http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=129

Wikipedia:     http://en.wikipedia.org/wiki/Gyrochronology