The oldest remnants of Earth-like planets were discovered 90 light-years away

The oldest known dead star with a host of rocky planetary remnants has been discovered just 90 light-years from Earth, providing insight into the formation of planetary systems and Earth-like planets help in the early universe.

This star is considered a white dwarf, the remnant of a star that has run out of hydrogen fuel in its core. Born as an ordinary star 10.7 billion years ago, just 3 billion years after the Big Bang, WDJ2147-4035 is actually one of two white dwarfs with planetary remnants recently discovered in data from the space agency's Gaia Galaxy Mapping Mission. Europa have been detected.

• A strange white dwarf has been discovered on the verge of a surprising evolution

Although these two first stars White dwarfs are not the ones seen collecting debris from the destruction of their planets, but they are the oldest and can therefore provide detailed insight into the composition of planets when the universe was less than 3 billion years old.

In the case of WDJ2147-4035, although its parent star was more massive than the Sun, it was still not massive enough to end its life in a supernova explosion. Instead, half a million years after its formation, about 10.2 billion years ago, it ran out of hydrogen fuel for the process of nuclear fusion in its core, and it continued to swell and become a red giant. It then ejected its outer layers to finally reveal its neutral, helium-rich core as a white dwarf. The red giant itself dominated the entire system, some of the planets orbiting it were either destroyed or disrupted, while others may have remained intact. Either way, these disturbances resulted in large amounts of debris and rotating planetary debris that have been falling onto the white dwarf ever since. A process that will happen to the solar system in the future.

• An exoplanet was discovered in the life belt of a dead star

According to an article published on November 5 (November 16) in the Monthly Notices of the Royal Astronomical Society, astronomers led by Abigail Elms, a PhD student at the University Varick, UK to study the chemical structure of the red star WDJ2147-4035 as well as the second star, the blue star WDJ1922+0233, from spectroscopic measurements of Gaia, the observatory's Dark Energy Camera. Victor M. Blanco in Chile and the X-Shooter instrument at the European Observatory in Chile.

The results of this survey show a surprising variety of planetary compositions. WDJ1922+0233's water, which gets its color not from temperature but from the unusual mixing of gases in its helium-hydrogen atmosphere, appears to be contaminated by materials similar to the composition of Earth's continental crust. "These metal-contaminated stars show that Earth is not unique and that there are other planetary systems with Earth-like bodies," Elms told the Star about the fallen planetary debris.

WDJ2147-4035 is red in color but has a more puzzle-like structure. The star is being enriched with lithium, potassium, sodium and some carbon contained in an accretion tablet White dwarfs fall. "The red star WDJ2147-4035 is a mystery because its accumulated planetary debris is rich in lithium and potassium and is unlike any known object in our solar system," Elms said. Either way, the new findings provide more evidence that rocky planets could have formed in abundance, even though heavy elements were less common in the universe in the distant past and had to be formed by later generations of stars. According to Elms, "The amazing thing is to know that this happened on a scale of 10 billion years, and that these planets died long before the Earth formed." in red and WDJ1922+0233 in blue
Credit: University of Warwick/Dr Mark Garlick

Source: Space