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12/22/2024 06:11:15 pm

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Astronomers get Better at Determining the Age of Stars

Stars

(Photo : en.wikipedia.org) A starry sky in the infinite universe.

Stars slow down over time, and this spin speed allowed astronomers to craft a clever method by which the age of stars can be better measured.

An international team of astronomers led by Dr. Soren Meibom from Harvard-Smithsonian Center of Astrophysics claimed they've now taken a significant step forward in developing a "cool star clock" that can improve the accuracy of stellar age determination.

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In the new study, Dr. Meibom and his team observed and surveyed 30 "cool stars" in the cluster NGC 6819.

Cool stars are solar-type stars about the size of the sun. These are the most common stars in the galaxy and host the majority of Earth-like planets.

"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," detailed Dr. Meibom.

The team managed to measure the rotational speeds of the cool stars with the use of NASA's highly sensitive Kepler space telescope.

Finally, astronomers used a method called "Gyrochronology," which was first proposed in 2003 by co-author Sydney Barnes, to give an age of 2.5 billion years for all of the stars in the NGC 6819 cluster.

Gyrochronology is an analytical approach for calculating the ages of stars based on their spin speeds in relation to their masses.            

By using gyrochronology, the relationship between a star's mass and its rotational rate was defined well enough that by measuring these parameters, stellar age can be determined with only a 10 percent uncertainty.

The new study, presented Jan. 5 at the 225th meeting of the American Astronomical Society in Seattle, Washington, and published in the journal Nature, can provide astronomers fresh knowledge on how various astronomical phenomena evolve over time. It can also help identify other Earth-like planets.

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