White dwarf’s double debris disc may hide two surviving planetary bodies

Calcium light from the white dwarf WD J1328–1450 shows four peaks instead of the usual two, which a team models as two separate gas rings; the two hidden planetary bodies they propose to explain it have not been seen.

Peer reviewed · Observational study · One star

A burnt-out star called WD J1328–1450 is circled by two separate rings of metal-rich gas, not the single ring seen around every other white dwarf of its kind. Nicola Pietro Gentile Fusillo of the University of Trieste and colleagues in the UK, Chile and Germany report it in Nature Astronomy. They propose that two surviving planetary bodies, each between a few kilometres and roughly Pluto’s size, keep the rings fed and apart. That would mean parts of a planetary system can outlast their star’s death. The bodies themselves are inferred, not observed.

Evidence at a glance

Is this a big deal?

A solid, unusual observation with a reasoned but unproven explanation. Two gas rings, where 21 earlier systems showed one, is new. Two hidden bodies is the authors’ best account, and it needs more stars like this one.

What scientists found

A white dwarf is the hot, Earth-sized core left when a star like the Sun runs out of fuel. This one is about 0.47 times the Sun’s mass, with a surface near 17,400 kelvin, and it has been cooling for roughly 73 million years (the estimate ranges from 47 to 122 million).

Calcium, magnesium and silicon in its atmosphere show it is swallowing rocky debris. Alongside one of the brightest dust discs known around a white dwarf sit two gas rings. The inner one spans 0.14 to 0.34 solar radii, about 97,000 to 237,000 km, closer than the Moon is to Earth. The outer one runs from 0.54 to 1.93 solar radii, from about the Earth–Moon distance out to 1.3 million km.

How they found it

Gentile Fusillo picked out the star from Gaia data and its extra infrared glow from warm dust. The team observed it with X-shooter in 2021 and again in May 2023.

The trick is in the shape of the emission lines. Think of an ambulance siren: its pitch rises as it comes toward you and drops as it moves away. Gas in an orbiting ring does the same with light. The side swinging toward us is shifted blue, the far side red, so one ring makes two peaks. Two rings orbiting at different speeds make four.

The analogy has a limit: nobody sees the ring’s two sides separately. The peaks are blended light, and the ring sizes come from a fitted model. Lead modeller Felipe Lagos-Vilches fitted the calcium lines with two flat, circular rings inclined about 77°, so we see them close to edge-on.

The magnesium line gave a second clue. It shows only two peaks, from the inner ring. Had the outer ring held magnesium in the same proportion, the team calculates, it would have shown at about 6 sigma. So the outer ring is low in magnesium, pointing to different parent material: two bodies, or crust and mantle from one layered body.

Why it matters to you

This won’t change anything in your daily life. It touches a question about our own future: the Sun will one day become a white dwarf, and systems like this one show which parts of a planetary system can survive that. The scale is easy to picture: the outer ring would reach about 3.5 times as far as the Moon is from Earth, yet gas in the inner ring circles its star in under an hour. For how stars reach this stage, see the life cycle of a star.

What the evidence does not show

Nobody has seen the planetary bodies; the authors argue for them by elimination. Gas made only at the dust disc’s inner edge could not leave a gap, and gas from colliding dust would need an unknown way to stop collisions in one band. Two unresolved white dwarfs, each with a disc, would need very fine-tuned conditions. A single disc whose thick inner part shades the region between 0.34 and 0.54 solar radii could produce similar lines, but the paper notes no existing theory backs that up.

The sizes are upper limits set by tidal forces, not measurements, and any body that close needs internal strength to avoid being torn apart. At iron-like density, the inner body could be at most 45 to 172 km across, depending on position. In the outer ring the ceiling reaches about 2,340 km for iron, or about 3,500 km for rock at the outer edge. For scale, Pluto is 2,377 km wide and the Moon about 3,480 km.

How this fits what we already knew

Gas discs around white dwarfs have been known for about 20 years. In 2019, Christopher Manser, a co-author here, and colleagues reported a solid body inside the gas disc of SDSS J1228+1040, found through a roughly two-hour repeating signal. It is the template for this paper: a planetesimal making gas as it interacts with dust. Two rings would need two.

Gas is also rare. In a 2025 survey by a separate group, L. Saker, M. Gómez and L. García searched 13 dusty white dwarfs with the Gemini telescope and found no calcium gas emission in any, suggesting the gas phase may last only part of a disc’s life.

Independent perspective

SciQuest found no comment from an astronomer outside the author team as of 27 October 2026, 07:12 UTC, and has not yet interviewed one. The paper’s peer reviewers are anonymous. The authors call the system a new challenge for the current models of debris disc formation and evolution.

How other headlines framed it

SciQuest found no other news coverage or press release when this article was prepared. We will add a comparison if credible outlets report on the study.

What happens next

The authors say the system adds observational constraints for more detailed models of these discs, and note its rings resemble those in discs around newborn stars. In SciQuest’s view, the useful next steps are repeat spectra to watch for changes and a hunt for more four-peaked white dwarfs.

In one sentence

A white dwarf with two separate gas rings, read from four-peaked light, may be feeding on two surviving planetary bodies, but those bodies are still an inference from one star.

Read next

• White dwarf colours: most look white, a few would glow green or pink: what these stars would look like up close.
• Life cycle of a star: how a Sun-like star ends as a white dwarf.
• How many planets are there in the Milky Way? The population these survivors came from.

Sources and disclosure

1. Gentile Fusillo NP, Lagos-Vilches F, Gänsicke BT, Manser CJ, Koester D. “A double debris disc around a white dwarf sculpted by two planetary bodies.” Nature Astronomy, published 26 October 2026. doi:10.1038/s41550-026-03004-3 (full text read on nature.com).
2. Manser CJ et al. “A planetesimal orbiting within the debris disc around a white dwarf star.” Science 364: 66–69 (2019). doi:10.1126/science.aat5330.
3. Saker L, Gómez M, García L. “Gaseous disks in white dwarfs: properties of the current sample.” Accepted in Revista Mexicana de Astronomía y Astrofísica (2025). arXiv:2509.05180.
4. NASA Science, Moon facts and Pluto facts; IAU 2015 Resolution B3, arXiv:1510.07674 (nominal solar radius 695,700 km).

Disclosure: This article was drafted with AI assistance and checked against the sources above, including the full open-access paper. The authors declare no competing interests. Calculations by SciQuest: kilometre distances use 1 solar radius = 695,700 km; orbit times assume circular orbits around a 0.47-solar-mass star (about 13 to 48 minutes in the inner ring, 1.6 to 11 hours in the outer). The graphic is a SciQuest original built from the paper’s values. Spotted an error? See our corrections policy.