A study published in Nature Astronomy on Oct. 5, 2026, reports that the white dwarf star HS 0209+0832 may host a second-generation planet formed from stellar debris. The white dwarf is located approximately 270 light-years from Earth. Primary source: science.nasa.gov

Jamie Williams, the lead author of the study and a doctoral candidate at the University of Warwick, said the findings suggest planetary systems may have longer evolutionary histories than previously thought. "Rather than the white dwarf stage being a kind of epilogue to the story of a star and its planets, this research points to the systems we are familiar with only being the first chapter of a potentially much longer tale, with some new characters showing up," Williams said. "In a regular white dwarf there’s no disc, because the star’s material will just be ejected outwards during the red giant phase," he said. Primary source: science.nasa.gov

Boris Gaensicke, an astronomer and study co-author at the University of Warwick, said he was surprised by the finding. "When Jamie asked me about niobium in relation to this study I was truly gobsmacked, as that element had not been reported in any other white dwarf analyzed to date," Gaensicke said. "I think this research is an important example of the fact that scientific discovery is not a straight path," he said. Primary source: science.nasa.gov

The research team confirmed Hubble observations using data from NASA's retired Far Ultraviolet Spectroscopic Explorer (FUSE) mission. Researchers found almost no silicon or iron in the system, which are the main ingredients of rocky planets. Primary source: science.nasa.gov

NASA’s Transiting Exoplanet Survey Satellite (TESS) observed the white dwarf for four months. TESS detected periodic brightness variations indicating a planet orbits the white dwarf at a distance of about 3.7 million miles (6 million kilometers). The signal repeated every 4.4 days. Primary source: science.nasa.gov

The candidate planet is estimated to be a gas giant about the size of Jupiter. It is rapidly losing atmosphere due to energy from the hot white dwarf star. "It’s not a confirmed planet. It’s only a candidate for now," Williams said. Primary source: science.nasa.gov

David J. Wilson, a study coauthor and research associate at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder, said the debris environment around white dwarfs makes planet formation plausible. "Although white dwarfs don’t form via supernova, they are surrounded by debris. You have the planets that were lucky enough to survive the star’s giant phases, the shattered remains of those that weren’t, and leftover gas and dust ejected by the star as it turned from a giant to a white dwarf. So it’s a compelling idea that all that stuff might coalesce into new planets," Wilson said.

"The sun will eventually become a white dwarf, so we’re also looking at the future of the solar system here — maybe the Sun will get a new planet someday!" he said.

Why It Matters

The University of Warwick has a history of research into planetary systems around white dwarfs, including studies on the accretion of planetary debris onto these stellar remnants. In 2019, the University of Warwick's Department of Physics contributed to the discovery of a potentially habitable exoplanet orbiting a red dwarf star, demonstrating its ongoing role in planetary science and astrophysics research. The University of Warwick has a long history of astrophysical research, including contributions to planetary science and stellar evolution. It is known for its strong collaboration with international space agencies and has hosted multiple projects related to exoplanet detection and characterization.

Jamie Williams, the lead author of the study, is a doctoral candidate at the University of Warwick and has previously contributed to research on planetary systems and white dwarf accretion. The Hubble Space Telescope, launched in 1990, has been instrumental in uncovering the chemical composition of celestial objects, including the white dwarf HS 0209+0832. Its Far Ultraviolet Spectroscopic Explorer (FUSE) mission, which operated from 1999 to 2009, was used to confirm the presence of niobium in the system. The Hubble Space Telescope first observed HS 0209+0832 in 1999, and the unusual chemical signatures in its atmosphere were not fully understood until recent reanalysis using updated spectral databases and additional data from FUSE and UVES.

Timeline

Hubble first observed the star HS 0209+0832 in 1999. A study regarding the white dwarf star HS 0209+0832 was published in Nature Astronomy on Oct. 5, 2026. An artist’s concept depicting the possible second-generation planet around HS 0209+0832 was released on Oct. 5, 2026. Primary sources: science.nasa.gov, nasa.gov

What's New

Later reporting includes statements from the research team regarding the implications of the findings. "What Hubble is showing us in this white dwarf system is something we haven’t seen before: a high abundance of the element niobium, the signature of which I was unfamiliar with when I first found it in the archival data," Williams said. "If the second-generation planet is there, I think it is likely to survive. Eventually the white dwarf will cool and then maintain a consistent temperature, with the planet in its stable habitable zone for millions of years," he said. Primary source: science.nasa.gov

Additional context provided by the team notes that "Niobium and other elements heavier than iron are astronomically special because, unlike many common elements, they are not formed in the cores of stars by thermonuclear fusion," according to reports. "What’s interesting about planets orbiting close to white dwarfs is that because white dwarfs cool over time, their habitable zone is very stable. A second-generation planet could form and then be in the habitable zone for tens of billions of years," he said. NASA’s Transiting Exoplanet Survey Satellite (TESS) observed HS 0209+0832 for four months and detected periodic brightness variations indicating a potential planet orbiting at a distance of about 3.7 million miles. Primary source: science.nasa.gov