ESO discovers a double gas-and-dust disk around a white dwarf

The European Southern Observatory (ESO) announced on October 27, 2026, the discovery of a debris disk around the white dwarf WD J1328–1450, the stellar remnant under study. ESO’s announcement describes a double structure separated by a gap and suggests that two planetary bodies could shape it and have survived the star’s violent transformation. One of these bodies could be comparable in size to Pluto.

The scientific findings are presented in a paper in Nature Astronomy. The authors analyzed emission lines from the gas surrounding the white dwarf: instead of the two-peaked profile observed in the 21 known gaseous disks they cite for comparison, the lines from WD J1328–1450 show four peaks. The paper attributes this shape to the superposition of emission from two concentric gaseous rings.

Two rings separated by a gap

By fitting the lines, the team modeled an inner ring extending from 0.14 to 0.34 solar radii and an outer one from 0.54 to 1.93 solar radii. The model assumes circular, coplanar rings with surface brightness that changes with distance from the star. The nearly symmetrical profiles remained unchanged for more than two years, which, according to the authors, supports the hypothesis of gaseous disks that are close to circular and uniform.

The paper proposes that the structure is caused by two distinct planetary bodies located in the disks, ranging in size from a few kilometers to that of Pluto. This is a proposed explanation for the observed configuration. ESO’s announcement summarizes the possibility as two bodies that may have survived the star’s violent death and shaped the disk.

Signs of differences between the rings

The study also reports differences in lines associated with different elements. Magnesium lines show a two-peaked profile that the team links to the inner ring. If both rings had the same calcium-to-magnesium ratio, the model predicts a magnesium signal from the outer ring that should have been detectable at a significance greater than 6σ. According to the authors, the absence of that signal is independent evidence within the model that the outer ring is depleted in magnesium relative to the inner one.

The researchers consider that this difference could indicate that the rings originated from different parent bodies with different formation histories, or from different layers of a differentiated body. These are possible interpretations of the inferred composition, not a conclusive identification of the origin of each ring.

The disk also shows an infrared excess attributed to dust. The paper estimates that the disk’s infrared emission is equivalent to 2.7% of the star’s flux and notes that it is among the brightest dusty disks published to date. The model that reproduces this excess places the dust’s inner edge at 0.25 solar radii and its outer edge at 2 solar radii. The authors caution that several fit parameters are degenerate and that other disk configurations could explain the data equally well.

What remains open to interpretation

The two-ring model provides a good fit to the four-peaked lines, but the paper notes an alternative: a single disk with vertical extent that causes self-occultation in the region between 0.34 and 0.54 solar radii could produce a similar result. The authors state that this alternative is not supported by existing theoretical models of debris disks around white dwarfs.

A small discrepancy also remains between the model and the observed intensity in a blue wing of the nested profiles. The team suggests that it could be due to a non-uniform gas distribution in the inner ring or a moderate departure from circular symmetry. However, it finds no evidence of disk precession in the observations, which would be expected if there were an eccentric orbit.

In measurements of the stellar atmosphere’s abundances, the study finds a magnesium-to-silicon ratio that is low compared with the usual values in other white dwarfs accreting debris. The authors caution that magnesium abundance was assessed using a single line, possibly blended with an emission signal, and therefore could be underestimated. They also suggest that the disk may have formed recently and that material accretion may not yet have reached a steady state.

ESO presents the system as a possible glimpse of what might happen to the Solar System. The discovery provides a case in which a gas-and-dust structure around a dead star can be studied through its emission lines and infrared radiation; the explanation involving two rings and the role of surviving bodies remain the team’s interpretation of the system.