Astronomers Find Debris Rings Around a White Dwarf That May Hint at the Solar System's Future
Astronomers at the European Southern Observatory have found a gas disk with two rings around the white dwarf J1328−1450. Researchers say it reflects a process that could one day play out in our own solar system.
Astronomers at the European Southern Observatory (ESO) have discovered a debris disk with an unusual structure around the white dwarf star J1328−1450: two distinct rings of gas separated by a gap. Researchers say such structures could offer clues about how the solar system will end once the sun runs out of fuel.
A white dwarf is the remnant of a star that has burned out. J1328−1450 lies about 1,600 light-years from Earth. Astronomers already knew of it from star-mapping catalogs, but new observations with ESO's Very Large Telescope revealed the disk surrounding it.
How the disk may have formed
According to the observatory, the disk is most likely what remains of a planetary system that once orbited the star. The star passed through a red giant phase and then became a white dwarf. In the process it may have destroyed some of its planets and exposed other rocky bodies to an extreme environment. Some of the released material formed a disk of gas and dust around the dead star.
The same process could repeat in our solar system. In about 5 billion years the sun will exhaust its fuel and expand into a red giant, potentially engulfing nearby bodies such as the closest planets. It will then shed its outer layers and leave behind a white dwarf. Any rocky bodies that survive could break apart and form a debris disk.
Two possible bodies
The two-ring structure suggests the disk is shaped by bodies astronomers have not yet been able to identify directly. The data indicate that at least two planetary objects may have survived the star's transformation. They could differ greatly in size: the one nearest the white dwarf would be only a few kilometers across, while the more distant one could be as large as Pluto or even the moon.
Their interaction with the surrounding material would explain how the two rings formed, although their existence as separate objects has not been confirmed. An alternative explanation is that the structure comes from different parts of a single planet-like body, such as its crust and core.
