Astronomers discover potential second-generation planet orbiting white dwarf

Astronomers have identified a potential “second-generation planet” orbiting the white dwarf HS 0209+0832, located approximately 790 light-years from Earth. This discovery, published in Nature Astronomy, suggests the planet may have formed from the material expelled by its parent star during its death throes as a red giant.

Researchers from the University of Warwick and other international institutions used data from NASA’s Hubble Space Telescope and the TESS satellite to identify unusual chemical signatures in the white dwarf’s atmosphere. Unlike typical stellar remnants, which usually show traces of silicon or iron, HS 0209+0832 contains exceptionally high concentrations of heavy elements, including zinc, copper, and notably niobium. The abundance of niobium is more than 1,000 times higher than that found in the Sun, serving as a chemical fingerprint of material processed during the star's final nuclear stages.

While first-generation planets form alongside their stars, this candidate appears to be a gas giant that condensed from the debris left behind after the star collapsed. This finding provides critical insights into the potential future of our own solar system, as the Sun is expected to become a white dwarf in approximately six billion years.