Plate Nº 83 · recorded October 10, 2026
Space & AstronomyReported finding
The phoenix planet: Astronomers spot a world rebuilt from stellar ashes
Astronomers have identified the first likely second-generation planet candidate around a white dwarf, a Jupiter-sized gas giant that appears to have formed from the very material its dead star cast off.
By Marcus Bennett3 min read623 words
In brief
- Niobium was detected in a white dwarf for the first time, at levels more than 1,000 times higher than those in the Sun.
- NASA's TESS satellite recorded a brightness dip repeating every 4.4 days, consistent with a Jupiter-sized gas giant in a tight orbit.
- The candidate planet orbits the white dwarf HS 0209+0832, identified by a University of Warwick-led team.
- The study was published in Nature Astronomy in 2026; DOI: 10.1038/s41550-026-02983-7.
- Lead author Jamie Williams is a PhD student at the University of Warwick; co-authors include Nicholas Stone (Wisconsin-Madison) and Boris Gänsicke (Warwick).
Astronomers have spotted the first likely second-generation planet ever found orbiting a white dwarf. The world — a Jupiter-sized gas giant — appears to have condensed from the very material its dead star cast off. The discovery, published in Nature Astronomy, centers on the white dwarf catalogued as HS 0209+0832.
Lead author Jamie Williams, a PhD student in the University of Warwick's Department of Physics, called it "a bit like finding a planet that has risen from the ashes of the very star it once orbited." Second-generation planets, Williams explained, are worlds that "form out of the material a star casts off as it dies."
What makes this planet different?
White dwarfs are the collapsed cores left behind when stars like the Sun run out of fuel. They pull in nearby planetary material, and astronomers can read the chemical signature of that debris in the star's atmosphere.
HS 0209+0832 stood out. Its atmosphere carried unusually heavy elements:
- Zinc
- Copper
- Niobium, at levels more than 1,000 times higher than those in the Sun — the first time niobium has ever been detected in a white dwarf
Dr. Nicholas Stone, an astronomer at the University of Wisconsin-Madison, identified the pattern as a telltale sign of the "s-process," a nuclear reaction that builds heavy elements inside stars during their bloated red-giant phase. "It's a chemical signature no ordinary, 'first-generation' planet should carry," Stone said, "which told us that this new planet was something different."
How did a new planet form around a dead star?
The team's interpretation: as the original star died and shed its outer layers, a companion star likely pulled that expelled gas into orbit. That companion's gravity seeded a fresh protoplanetary disk, and a new giant planet condensed from material rich in the heavy elements forged during the red-giant phase. That same material explains the unusual chemistry now raining onto the white dwarf.
"Forming the protoplanetary disk in this situation is not easy and helps explain why these planets are so rare," Williams said.
What did NASA's TESS satellite see?
Independent support came from NASA's Transiting Exoplanet Survey Satellite (TESS). Researchers detected a faint, regular brightness dip repeating every 4.4 days — the signature of a Jupiter-sized gas giant passing in front of the white dwarf.
The orbit sits so close to the stellar remnant that the planet is probably tidally locked, one side permanently facing the dead star. At that distance, the white dwarf's intense radiation should be boiling away the planet's outer atmosphere. The escaping gas, laden with zinc, copper, and niobium, rains onto the white dwarf and produces the chemical fingerprint the team spotted.
Could more phoenix planets exist — even around our Sun?
Boris Gänsicke, a professor in Warwick's Department of Physics, framed the find as a search template. "What's remarkable about the planet around HS 0209+0832 is that this isn't a planet from somewhere else, or a survivor from the system's birth," he said. "It looks like it was built from the very material its own star cast off as it died."
If confirmed, HS 0209+0832 would be the first white dwarf known to host a second-generation planet. The discovery opens a new way to hunt for similar reborn worlds: by scanning other white dwarfs for the same carbon and heavy-element signature.
Gänsicke raised the long-term stakes: "Finding this one example raises the question of how many more might be out there — and might our own solar system host a second-generation planet formed from the ashes of our Sun?"
Published in Nature Astronomy (2026). DOI: 10.1038/s41550-026-02983-7.
via Phys.org Space & Astronomy (Source)
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