A newly examined clue in NASA’s Hubble Space Telescope archive suggests the white dwarf star HS 0209+0832 could host a rare type of world: a possible second-generation planet.
In a study published Monday in Nature Astronomy, researchers reported finding unusual chemical abundances in the system. The team says the evidence may be explained by a planet that formed around the white dwarf from material the star expelled as it evolved.
White dwarfs are the remaining cores of low-mass stars after they exhaust their nuclear fuel and lose their outer layers of gas and dust. A second-generation planet, by contrast, would form later from that cast-off material.
Earth and the other planets in the solar system are first-generation planets, formed from matter left over from the Sun’s birth. Jamie Williams, the study’s lead author and a doctoral candidate at the University of Warwick in the United Kingdom, said the findings raise the prospect that planetary systems may continue developing after a star reaches its white dwarf stage.
NASA describes the proposed planet around HS 0209+0832 as a possible explanation for the Hubble observations, rather than a confirmed discovery.
