- HD 219134 is an orange star cooler than our solar about 21 light-years away from Earth. It has a household of 5 identified planets.
- Astronomers listened to the “music” – refined inside vibrations – of the star, utilizing the Keck Observatory in Hawaii. They discovered the star is barely smaller than beforehand thought.
- The findings additionally present extra clues about how stars decelerate of their rotation as they become old. They usually assist astronomers measure the sizes and densities of its 5 planets.
Listening to a close-by star’s music
You might need heard of the music of the spheres or musica universalis. It was an historical Greek philosophical idea that regarded proportions within the actions of celestial our bodies as a type of music. Now, on Might 6, 2025, a world staff of astronomers utilizing the W. M. Keck Observatory in Hawaii mentioned it has listened to the “music” of a close-by star. The researchers mentioned the refined stellar vibrations revealed the star is smaller than beforehand thought, difficult scientists’ understanding of stars’ interiors and the way they decelerate as they age.
It additionally helped to raised measure the sizes and densities of the star’s 5 identified planets.
After all, stars don’t truly play music, however they do emit sound waves – refined vibrations or oscillations – that astronomers can examine. Astronomers can “hear” these pure frequencies utilizing the fitting devices. And that’s what the staff of astronomers did with the close by star HD 219134, 21 light-years away. They used the Keck Planet Finder (KPF) on the W. M. Keck Observatory in Hawaii to hearken to the star. Scientists name this method of listening to stars’ sound waves asteroseismology.
The vibrations can present clues in regards to the interiors of stars and different information. Lead writer Yaguang Li on the College of Hawaii at Manoa mentioned:
The vibrations of a star are like its distinctive music. By listening to these oscillations, we are able to exactly decide how large a star is, how massive it’s, and the way previous it’s.
The researchers printed their peer-reviewed findings in The Astrophysical Journal on Might 6, 2025.
Stellar songs from scorching and funky stars
HD 219134 is an orange star, cooler than our solar. It’s been simpler to detect such stellar vibrations from hotter stars. With HD 219134, the stellar songs are rather more refined and more durable to detect with most telescopes.
However the Keck Planet Finder is ideally fitted to this job. It could possibly exactly measure the movement of a star’s floor towards and away from the observer. Total, the astronomers listened to the star for 4 consecutive nights and picked up over 2,000 velocity measurements. These measurements have been extraordinarily exact. Li mentioned:
KPF’s quick readout mode makes it completely fitted to detecting oscillations in cool stars, and it’s the solely spectrograph on Mauna Kea presently able to making such a discovery.
Measuring the ages of stars
The oscillations inside stars may also present clues about their ages and what occurs as they become old. Younger stars rotate quickly, however then decelerate as they age. The researchers decided that HD 219134 is greater than twice the age of our solar, about 10.2 billion years previous. The solar and photo voltaic system are about 4.6 billion years previous. So its rotation is loads slower now than when it was youthful.
However the brand new evaluation of HD 219134 may also assist scientists perceive one other peculiarity. The slowing rotation, or spin-down, of stars much like HD 219134 tends to finally come to a halt. The asteroseismic information permits scientists to anchor stellar fashions on the oldest finish of a star’s lifetime. This, in flip, helps astronomers decide the ages of stars extra exactly. As Li famous:
That is like discovering a long-lost tuning fork for stellar clocks. It provides us a reference level to calibrate how stars spin down over billions of years.
Smaller than anticipated
The brand new asteroseismic measurements revealed one other shock, too. HD 219134 is barely smaller than astronomers thought it was. It’s about 4% smaller than earlier research had instructed. That doesn’t sound like loads, nevertheless it poses challenges for present stellar fashions, particularly for stars like HD 219134.
Why the discrepancy? The researchers mentioned it may very well be due atmospheric results in Earth’s ambiance, magnetic fields and even points with the stellar fashions themselves.
W. M. Keck Observatory: Astronomers Tune Into the Music of a Close by Star Unlocking a Shocking Discovery keckobservatory.org/hd-219134/
— AAS Press Workplace (@press.aas.org) 2025-05-06T15:40:20.100Z
A household of planets and extraterrestrial life
Like many – and even most – stars, HD 219134 has no less than 5 identified confirmed planets, and presumably extra, together with two super-Earths. Tremendous-Earths are rocky and bigger than Earth however smaller than Neptune. With the ability to higher refine the scale of the star additionally helped the researchers measure the sizes and densities of its household of planets as properly.
Keck Planet Finder and related devices will even be capable to help within the seek for life on exoplanets. Figuring out how previous the celebrities and planets are extra precisely will assist astronomers estimate how previous life is on a planet, whether it is discovered. Co-author Daniel Huber mentioned:
After we discover life on one other planet, we’ll wish to know the way previous that life is. Listening to the sounds of its star will inform us the reply.
Backside line: Astronomers have listened to a close-by star’s music – refined inside vibrations – to study extra about how stars’ rotation pace slows down as they age.
By way of W. M. Keck Observatory
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