“Star music” allowed researchers to discover the secrets of an aging star. Scientists measured the vibrations of the orange dwarf HD 219134, on the basis of which they determined the age and dimensions of a distant object. His oscillations were “translated” into audible frequencies, thanks to which we can listen to its activity.
Contrary to appearances, the stars are not quiet – these objects have their own frequencies on which they resonate. Although we can't hear them with our own ears, we can measure them with various research methods and instruments. The oscillations of a given star reveal a lot about it, from age to mass and dimensions. In the magazine “The Astrophysical Journal” a study of “Star Music” appeared, in which we have not had the opportunity to listen to so far.
Age -old but compact
Scientists carried out HD 219134 observations, an orange dwarf located 21 light years from Earth in the constellation of Cassiopea. This star is cooler than our sun, which makes it difficult to monitor its oscillation – cosmic telescopes are easily recorded by the frequencies of hot facilities. For this reason, the research team decided to use the ground instrument, the Keck Planet Finder spectrometer from the WM Keck Observatory in Hawaii. The equipment was designed to look for planets, but its specification perfectly match the purpose of the study – precise observation of changes on the surface of the object, enabling tracking its vibration.
Based on the collected data, the team determined the age of the star at 10.2 billion, which is more than twice as much as the age of our sun. It makes it one of the oldest stars of the main series, whose age was determined in this way. The exact determination of the age of the object is important when we combine them with the observation of the rotation speed. Young stars spin faster, but as aging they lose their momentum. The results obtained during the study give us a better insight into this process.
The band also discovered that HD 219134 seems smaller than expected. Previous measurements using interferometry – a star -size assessment techniques by observing with many telescopes – gave a ray about four times larger than an oscillating test.
In search of life
Scientists also transformed HD219134 oscillations into audible sound. The star pulsates about every four minutes. After properly accelerating the vibration, they go into a range audible to the human ear. “Listening” in this way the lights of the star, astronomers can study and activity under its surface.
HD oscillation 219134 measured with the Keck Planet Finder converted into audible soundGabriel Perez Diaz/Instituto de astrofísica de canarias
The study is important for one more reason. HD 219134 is not lonely – there are at least five planets around her, including two rocky worlds larger than the ground. Thanks to the precise measurements of the size of the star, the team was able to clarify the size and density of these planets. The results confirm that these bodies probably have a composition similar to the earth, with solid, rocky surfaces. Such measurements are especially important for astrobiologists looking for signs of extraterrestrial life.
– When we find life on another planet, we will want to know how old it is – said Daniel Huber from the Hawaiian University, co -author of the study. “Listening to the sounds made by her star will give us an answer,” he concluded.
Source of the main photo: Gabriel Perez Diaz/Instituto de astrofísica de canarias