Scientists have studied the pulsation of the star HD 219134 which is its peculiar “song”. Thanks to this, they were able to determine its exact age, radius and other parameters. The researchers believe that in this manner, such studies can be conducted on other luminaries in the future.
“Song” of the star HD 219134
Researchers working at the Keck Observatory in Hawaii recently published a study in The Astrophysical Journal, according to which they managed to listen to the song of the star HD 219134 close enough to the Sun, and now they know much more about it than before.
Of course, scientists haven’t gone crazy, and you can’t really hear the song story of our Sun or any other star, no matter how much you listen. However, each of the stars actually has its own purely mechanical vibrations as a giant object of glowing gas. And the rhythmic oscillation of the gas is what we usually call sound.
The rhythm of stars is not transmitted through the vacuum as an intrinsic oscillation. Theoretically, it can be sensed by continuously observing the surface of the luminary at high resolution. True, in practice the “songs” of stars are so weak that it works exclusively with the Sun and some of its largest relatives. And in the latter case, it succeeded solely because of space telescopes.
This is why scientists have not previously considered the rhythms of stars as a source of information about them. They were considered too weak for that. But now researchers have an instrument called the Keck Planet Finder located at the very same Keck Observatory, and it has allowed researchers to “hear the song” of HD 219134.
What the scientists learned
In general, Keck Planet Finder is designed to search for worlds outside the solar system. But to achieve this, it needs to track the oscillations of the stars with extremely high accuracy. Therefore, it can be used to capture the rhythm of even a small orange star like HD 219134.
This luminary is only 21 light-years away. Astronomers collected data on it for 4 nights. It was enough to find out that this luminary makes one seismic pulsation exactly for four days.
And based on the rhythm of HD 219134, the researchers managed to learn a lot of interesting things about it. For example, they managed to find that the age of the star is 10.2 billion years, that is, it is twice as old as our Sun. And this discovery is important not only on its own, but also in the context of other features of the star.
The fact is that thanks to the rhythm study, it was also possible to establish the rotational speed of HD 219134. Stars usually spin fastest at the beginning of their existence and gradually slow down. But the study shows that at the end of the luminary’s existence, the rate at which its rotation slows down may decrease, and now scientists want to find out exactly why.
It is also worth noting that the star HD 219134 has as many as five planets. And scientists have just managed to refine the radius of this luminary. So now as they pass between it and Earth, it will be possible to tell more accurately what they are.
According to phys.org
