Dead Star's Two-Ring Debris Disk Offers a Preview of Our Solar System's Fate

Astronomers using the European Southern Observatory's Very Large Telescope have found a ring of shattered material circling a dead star, a structure that may show what becomes of a planetary system once its sun burns out, according to Wired. The star, a white dwarf catalogued as J1328−1450, sits roughly 1,600 light-years from Earth.

Star-mapping catalogues had already recorded the object, but the new observations showed something unexpected: the surrounding debris is split into two separate bands of gas with an empty gap between them, Wired reports.

The observatory says the material most likely came from the planetary system that once circled J1328−1450. As the star swelled into a red giant and then shrank into a white dwarf, it may have wrecked part of its family of planets, exposing the surviving rocky survivors to harsh conditions. Debris thrown off in that upheaval eventually gathered into a disk around the stellar remnant.

A similar sequence could play out here. In about 5 billion years the sun is expected to run out of fuel and balloon into a red giant, possibly swallowing the innermost worlds. It would later cast off its outer layers and leave a white dwarf behind. Rocky bodies that endure that upheaval might crumble into a debris disk resembling the one now seen around J1328−1450.

The twin rings point to a second explanation. Their shape seems to be carved by objects that astronomers cannot yet see directly. The data suggest that at least two planetary bodies may have come through the star's transformation.

Those two objects could differ greatly in scale, the researchers believe. The inner one would span only a few kilometers across, while the outer one might rival Pluto or even the moon in size. Their pull on the surrounding material would account for the two bands, though it is not confirmed that they are distinct bodies. Another option is that the gap and rings arise from separate regions of one planet-like object, for instance its outer shell and its center.

The findings were reported by Wired, which credited ESO for the observations.