We are aware that mystery abounds in space. The recent discovery of a solar system that is very different from our own cosmic home by scientists adds curiosity.
The white dwarf star, which is the surviving heated core of a dead star similar to the sun, was discovered by researchers to be almost 10 billion years old. It is located 90 light-years away and is surrounded by a cemetery of fragments of planets known as planetesimals. These objects’ debris has been drawn in by the dim star. But this solar system is unique compared to our surroundings. Elements like lithium and potassium are abundant there. Importantly, there are no planets in our solar system with such a makeup.
Why was this early solar system in our Milky Way galaxy so distinct from other solar systems? How did it acquire a wealth of these materials, which were at the time uncommon?
Abbigail Elms, a PhD candidate at the University of Warwick who studies white dwarfs, told Mashable, “It is a complete enigma.” Monthly Notices of the Royal Astronomical Society, a science magazine, released the research this week.
This solar system is old, as was already mentioned. That implies that the white dwarf (designated WDJ2147-4035) and the solar system that surrounded it developed and perished before the sun and Earth were even created. According to Elms, the fragments of past planets that have been discovered near WDJ2147-4035 are the oldest planetesimals that have ever been discovered around a white dwarf in our galaxy.
How do scientists know what made up this ancient solar system?
Using the Gaia space observatory, they found this white dwarf as well as another of a same age. This far-off spacecraft is mapping the stars and galaxies in the universe while it orbits the sun. Following the discovery of these white dwarfs, the researchers used an instrument known as the “X-Shooter,” which is situated at a high altitude in Chile, to determine what elements are and are not present in the stars’ atmospheres (X-Shooter is a type of profoundly valuable astronomical tool called a “spectrometer”). Lithium, potassium, and sodium were discovered to have accreted, or been drawn in by gravity and gathered around, the old star in WDJ2147-4035. The researchers deduced (by running models of this solar system’s history) that since white dwarfs are composed of hydrogen or helium, the other rare elements must have come from the planets’ rocky remnants.
It’s interesting to note that the other white dwarf they found, WDJ1922+0233, differed greatly from the enigmatical one. It’s more recognisable. They discovered that this star had attracted planetary debris resembling the rocky crust of Earth. Although one solar system continues to be an oddity, the existence of other solar systems that are relatively similar to Earth proves that it is not the only solar system in the universe.
However, there are many abandoned planet graveyards in these two solar systems. Like the sun, more than 95% of stars undergo white dwarf evolution. They grow into enormous red gigantic giants as they near the conclusion of their existence, smashing or upsetting neighbouring objects. Before shedding its outer layers, our sun will engulf planets like Mercury, Venus, and possibly even Earth as it enlarges. The remnants of disintegrated planets and moons that the red giants left behind. A white dwarf star will make up the remnant star.