Two debris rings from destroyed planets found around white dwarf J1328-1450

Astronomers have described an unusual system around the white dwarf J1328-1450, located 1600 light-years from Earth, according to pravda.ru. The study was published in Nature Astronomy. Around the star the researchers found two rings of debris with a noticeable gap between them pravda.rupravda.rupravda.ruOpen source ↗.

The term "zombie planets" refers to bodies that, it would seem, should have disappeared long ago.

What was found around the star

A white dwarf is what a Sun-sized star turns into when its fuel runs out. Before that, the star becomes a red giant, swells and engulfs everything nearby. Debris discs around white dwarfs had been found before, but they always looked like a uniform flat ring. The double structure at J1328-1450 shows, according to the authors, that planetary systems can keep a complex arrangement even after their star dies.

The analysis showed that the debris is left over from destroyed planets whose composition is close to Earth's: calcium, oxygen, magnesium and iron. The fragments differ in size: one is comparable to an ordinary asteroid, the other is close in scale to the Moon or Pluto pravda.rupravda.rupravda.ruOpen source ↗.

What it says about the Solar System

Study leader Nicola Gentile Fusillo of the University of Trieste called it the first example of a system with a double disc and potentially two surviving planetary bodies. According to the scientists, these remnants are witnesses to how planets resisted complete destruction when their star began to expand.

The difference in chemical composition between the inner and outer rings indicates that the destroyed worlds were quite different in nature. In the researchers' view, this gives a key to the processes that take place at the very end of the life cycle of stellar systems.

The source compares the finding with the fate of the Sun. In about 5 billion years the Sun will exhaust its hydrogen, become a red giant and will probably engulf the inner planets, including Earth. Studying J1328-1450 helps researchers understand what will remain of the planets after the Sun becomes a white dwarf pravda.rupravda.rupravda.ruOpen source ↗.