Astronomers at the University of Warwick have found evidence of a planet that formed from material shed by a dying white dwarf, infohub.kz reports.
The researchers analyzed old archival data from the Hubble telescope, collected back in 1999 during observations of the white dwarf HS 0209+0832. At the time, scientists were unable to identify about a hundred chemical lines in the star's spectrum. By comparing those records with a modern chemical database, the researchers determined that the spectral traces belong to niobium.
The level of this rare element in the system under study turned out to be 1,000 times higher than in our Sun. Niobium forms only under extreme conditions inside dying stars. Such a concentration indicates that a second-generation planet formed from material ejected by the star. Unlike first-generation planets, which are born together with their stars, these objects form from the remnants of a dying star.
White dwarfs are dense cores of stars that have exhausted their compressed nuclear fuel. The newly detected object currently lies in the habitable zone and is being intensely heated, which is gradually stripping away its outer layers. If the astronomers' conclusions are confirmed, HS 0209+0832 will become the first known white dwarf with a formed second-generation planet.