New Ultrasound Technique Tells Astronomers the Age of Baby Stars in Stellar Womb

Finding out exactly how old a star might be has long been a challenge for astronomers. Now, though, researchers may have found a way to do so. They've shown that they can tell the difference between infant and adolescent stars by measuring the acoustic waves that they emit.

Stars are often born in clusters as a result of contracting molecular clouds of gas and dust particles. As the star evolves over time, gravitational pull causes it to contract and it becomes smaller in size and hotter until the core temperature is hot enough to start burning hydrogen. At this point, the star stabilizes itself and becomes an "adult."

Yet finding out whether a young star is an infant or an adolescent is no easy task. That's why the researchers turned to acoustic vibrations, which are produced by radiation pressure inside stars. More specifically, the scientists looked at the vibrations of 34 stars aged under 10 million years and sized between one and four times the mass of our own sun.

"Our data shows that the youngest stars vibrate slower while the stars nearer to adulthood vibrate faster," said K. Zwintz, one of the researchers, in a news release. "A star's mass has a major impact on its development: stars with a similar mass evolve slower. Heavy stars grow faster and age more quickly. We now have a model that more precisely measure the age of young stars. And we are now also able to subdivide young stars according to their various life phases."

The findings could help researchers determine the ages of future stars. By examining several young stars and creating a model, they can then apply this research to others stars in more remote locations in order to determine exactly how old they might be.

The findings are published in the journal Science.