Niobium in old Hubble data points to a possible planet born after its star died

NASA reported on October 5, 2026, that a new analysis of archival Hubble Space Telescope data points to a possible second-generation planet orbiting the white dwarf HS 0209+0832. Hubble detected an unusual amount of niobium in the system, which researchers interpret as a clue that planetary material formed from matter expelled as the star died.

A white dwarf is the remnant core of a low-mass star after it exhausts its nuclear fuel and sheds its outer gas and dust. A second-generation planet would form later around that remnant from the cast-off material.

A possible gas giant feeding the star

The research team estimates that the candidate is a gas giant about the size of Jupiter and is rapidly losing atmosphere. Because the white dwarf is relatively new and remains very hot, the researchers think its energy is probably stripping the planet's outer material.

Under that proposed explanation, the escaping material could create a comet-like tail and a disk around the white dwarf before falling onto the star's surface, accounting for Hubble's niobium detection. NASA's depiction of the system is an artist's concept of this possible explanation rather than a direct image of the planet.

The candidate still needs confirmation

Researchers still need to determine how second-generation planets form, how common or rare they are and how their orbits evolve around white dwarfs. Williams plans to use Hubble over the next several years to build a larger body of data and statistics about such objects.

Williams said that if the planet exists, it is likely to survive the current atmospheric loss. He expects the white dwarf eventually to cool and maintain a consistent temperature, potentially leaving the planet in a stable habitable zone for millions of years. That conditional projection concerns temperature and orbit; it does not establish that the candidate gas giant is habitable.