© University of Warwick/Dr. Mark Garlick
Astronomers have discovered the remains of one of the oldest planetary systems in our galaxy. Proof of this was provided by 2 white dwarfswhoever 90 and 120 light years is far from the earth. You should redo 10 billion years be old.
White dwarfs are the cores of extinct stars. These were not massive enough to explode in a supernova and become a black hole or neutron star. Instead, they have lost their outer shell and are now cooling. They have high density but low brightness.
10.7 billion years old
The researchers of University of WarwickVK, made models of 2 white dwarfs with the space telescope GAIA we have been discovered. With their simulation, they wanted to know how long the nuclei had cooled. For this they used data from GAIA, the Research into dark energy and the spectrograph “X-Shooter” ben European Southern Observatory (ESO).
The study found that the star WDJ2147-4035 formerly 2.5 solar masses was heavy and about 10.7 billion years is old. Ever since 10.2 billion years it cools down like a white dwarf. he shines reddish and consists of Sodium, Lithium, Potassium and carbon. This makes it the oldest metal-laced White Star discovered to date.
the second star, WDJ1922+0233, is a bit younger. He is chilling 9 billion years away. However, his exact age cannot be determined yet. he shines bluewhich is due to the unusual atmosphere helium-hydrogen mixture lies.
Oldest system of the Milky Way
The rubble in the the atmosphere of red WDJ2147-4035 are from an ancient planetary system. It survived the star’s transformation into a white dwarf, but was then swallowed by the white dwarf, the scientists write. This makes it the oldest planetary system in the world Milky Way.
“These metal-contaminated stars are not unique, there are other systems with Earth-like planets. 97 percent of all stars become white dwarfs. Because they are so ubiquitous, it is very important to understand them,” said the study leader Abigail Elms in a statement. They are formed from the oldest stars in our galaxy and therefore contain information about how the first planetary systems formed.
In fact, astronomers can use the metals to understand the amounts in which they were present on the planets that were “devoured” by the white dwarf. In the case of WDJ1922+0233 this is clear: Here you can find yourself sodium, calcium and potassium. From the quantity, the team infers that a planet was devoured whose crust had a composition and mass similar to Earth’s.
With the reddish WDJ2147-4035, the discovery remains mysterious. “The enriched planetary debris is rich in lithium and potassium and unlike anything in our own solar system. The white dwarf is because of its metal impuritiesto be very cold surfacehis advanced age and the fact that he magnetic is extremely rare,” says Elms.
At the time these stars formed, there were fewer metals in the universe. Metals are created by gigantic stellar explosions and in the formation of stars. The two white dwarfs would provide a glimpse of how planetary systems formed in environments with few metals but many gases, the researchers said. The results of the study have been published in the journal Monthly Notices of the Royal Astronomical Society.