Stars litter our skies with celestial light, continually cementing the fact that our planet, no matter how large it may seem, is just a grain of sand on the beach that is our shared universe. And, for years, astronomers have gauged a star's age by how brightly it shined. While this is moderately effective, another method has been tested-and-proven to be more accurate. Published in the newest issue of the journal Nature, astronomer's note that how quickly a star spins is the ideal metric to determining its age.
Ideally, astronomers would like create a clock-like device that could precisely measure a given star's age, based on its rotational speed in relation to its mass.
"Our goal is to construct a clock that can measure accurate and precise ages of stars from their spins. We've taken another significant step forward in building that clock," said Soren Meibom, a member of the Harvard-Smithsonian Center for Astrophysics. "We have found that the relationship between mass, rotation rate and age is now defined well enough by observations that we can obtain the ages of individual stars to within 10 percent."
Much like humans, which tend to slow down with age, literally and metaphorically, stars display a distinct change in their spinning behavior as they grow in age. Though researchers have yet to exactly quantify the spins, they do have an idea about how they slow down.
"Let's imagine that we're born as small babies, but by our first birthday, we look like an adult, and we stay looking the same through our 20s and 40s and 60s, even 80s, until we suddenly appear old," Meiborn comments. "A cool star spins very fast when it's young, but just like a top on a table it gets slower and slower as the star grows older."
This ground-breaking measuring tool will help astronomers create what could be essentially a timeline of a said solar system, galaxy, etc.. And that has far greater applications than what people may think.
"Now we can derive precise ages for large numbers of cool field stars in our Galaxy by measuring their spin periods" Meiborn says. "This is an important new tool for astronomers studying the evolution of stars and their companions, and one that can help identify planets old enough for complex life to have evolved."
