Astronomers have discovered a very old and very mysterious solar system. Presentation.
L’Space is full of mysteries. And experts are constantly uncovering exciting new plots. Recently, astronomers found an old solar system very, very different from ours.
About 90 light-years away, researchers discovered a white dwarf more than 10 billion years old – in other words, the hot core of a dead star similar to our Sun – which is surrounded by a graveyard of pieces of planets, planetesimals. This failing star attracted debris from these objects. But this solar system is unlike anything known near us. It is full of elements like lithium and potassium. No planet in our solar system has such a composition.
Why then was this ancient solar system so different? How did he become so rich in these materials which were very rare at the time?
“It’s a complete mystery,” says Abbigail Elms, a student at the University of Warwick who studies white dwarfs. The results were published this week in the scientific journal Monthly Notices of the Royal Astronomical Society.
As noted above, this solar system is old. This means that the white dwarf (exactly named WDJ2147-4035) and its surrounding solar system formed and died before the Sun and Earth were born. In truth, the pieces of ancient planets around WDJ2147-4035 are the oldest planetesimals ever discovered in our galaxy around a white dwarf.
How did astronomers discover the composition of this archaic solar system?
Experts discovered this white dwarf and another of a similar age using an observatory in space called Gaia. In orbit around the Sun, this spacecraft maps the stars and galaxies in the cosmos. After discovering these white dwarfs, the researchers then activated an instrument called “X-Shooter” – more precisely a spectrometer -, located in Chile, at altitude, to detect what is or is not present in the atmospheres of stars. . In WDJ2147-4035, they found elements like lithium, potassium, and sodium. White dwarfs are formed from hydrogen or helium, so rocky remains of planets are the source of other unique elements, the researchers say. A conclusion to which they reached by carrying out simulations on the evolution of this solar system.
The other white dwarf (WDJ1922+0233) they discovered is significantly different from the first. She is more familiar. They found that this star had attracted debris from similar planets similar to our Earth’s rocky crust. Thus, if one of the solar systems remains an anomaly, at this point, the other shows that the Earth is not unique in the cosmos: there are other solar systems very similar to ours.
Both of these systems, however, are full of remnants of ancient planets. More than 95% of stars, like the Sun, evolve into white dwarfs. Towards the end of their life, they become colossal red giants, destroying surrounding objects. When it will be the case of our sun, it will gobble up planets like Mercury, Venus, and possibly even Earth before shedding its outer layers. The red giants leave behind relics of annihilated planets and moons, and what remains of the star itself is a white dwarf. “Our sun will evolve into a white dwarf in about 5 billion years,” says Abbigail Elms.
A new study has identified the oldest star with an evolved planetary system in our galaxy…
And this 10 billion year old white dwarf is only 90 light years away from Earth 🚀
Read the full story: https://t.co/zIlRZehOJI
📸: Dr Mark A Garlick pic.twitter.com/gqBsgZZ9lt
— University of Warwick (@warwickuni) November 7, 2022