\n When a sunlike star dies, it first rapidly expands into a red giant<\/a> and then sheds its outer layers, leaving behind a much smaller but dense, hot core \u2014 known as a white dwarf. Some of the first-generation planets, those that originally formed at the same time as the star, can survive this cataclysmic event if their orbit is wide enough. Astronomers have observed a handful of such first-generation survivors revolving around white dwarfs, but never before have they recorded a so-called second-generation planet \u2014 an entirely new world made from a dead star\u2019s debris.\n <\/p>\n \n The telltale sign that HS 0209+0832 might have birthed a new planet is unusual traces of heavy elements on the white dwarf\u2019s surface that the study authors believe is planetary material raining down onto the leftover core. \u201cThis planetary material is very rich in an element called niobium,\u201d said lead study author Jamie Williams, a doctoral student in the department of physics of the University of Warwick in England. \u201cIt\u2019s the first time that this element is found in a white dwarf, and this implies that the planetary material is made from the ashes of the star as it died.\u201d\n <\/p>\n \n Further analysis of observations from NASA\u2019s Transiting Exoplanet Survey Satellite<\/a> or TESS revealed a faint brightness signal repeating every 4.4 days \u2014 evidence that the researchers say is consistent with a giant planet orbiting the white dwarf.\n <\/p>\n \n \u201cWhat\u2019s interesting about planets orbiting close to white dwarfs is that because white dwarfs cool over time, their habitable zone is very stable. A second-generation planet could form and then be in the habitable zone for tens of billions of years,\u201d Williams said.\n <\/p>\n \n Such a large period of stability could provide more ideal conditions for life, but more work is required to validate the second-generation planet discovery, he added. \u201cIt\u2019s not a confirmed planet,\u201d Williams said. \u201cIt\u2019s only a candidate for now.\u201d\n <\/p>\n \n After the red giant phase when a dying star quickly puffs up, it becomes a nuclear furnace that can produce various elements. However, once that fuel runs out and the star transforms into a white dwarf, the heavy elements \u2014 including nobium \u2014 sink downward rapidly, leaving only lighter elements such as hydrogen and helium on the surface. The researchers determined that the niobium detected on HS 0209+0832 must therefore come from the star\u2019s surroundings. \u201cWe think these elements fell onto the white dwarf\u2019s surface because the white dwarf is very hot and emitting loads of extreme ultraviolet radiation, which is stripping the atmosphere of a nearby planet,\u201d Williams said.\n <\/p>\n \n The idea of second-generation planets has existed for at least as long as astronomers have known about exoplanets, said study coauthor David J. Wilson, a research associate at the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder.\n <\/p>\n \n Scientists detected the very first exoplanets around a pulsar<\/a> \u2014 a type of rapidly rotating dead star \u2014 and because pulsars form as a result of massive explosions called supernovas, these planets are likely second-generation, as any original planets would have been destroyed by the immense blast, Wilson explained.\n <\/p>\n \n \u201cAlthough white dwarfs don\u2019t form via supernova, they are surrounded by debris,\u201d he said via email. \u201cYou have the planets that were lucky enough to survive the star\u2019s giant phases, the shattered remains of those that weren\u2019t, and leftover gas and dust ejected by the star as it turned from a giant to a white dwarf. So it\u2019s a compelling idea that all that stuff might coalesce into new planets.\u201d\n <\/p>\n \n Astronomers still don\u2019t know all the details about how first-generation planets form, which means the potential mechanisms behind this newly reported second-generation planet are even more uncertain. The planet-forming process might have derived from a collision between the dying star and a second celestial body, according to Williams. \u201cThere could have been another object close to the core of the star, maybe a star around 20% the mass of the sun, or a brown dwarf,\u201d said Williams, referring to a class of cool objects that are an intermediate between a star and a planet.\n <\/p>\n \n If a second object fell into the star during its giant phase, it could have prevented all the dust and gas from spreading out into a massive cloud, making some of it spin in a disk. This disk would then have continued to rotate around the white dwarf, birthing a planet. \u201cIn a regular white dwarf there\u2019s no disc, because the star\u2019s material will just be ejected outwards during the red giant phase,\u201d Williams added.\n <\/p>\n \n The researchers plan to use Hubble and NASA\u2019s Chandra X-ray Observatory<\/a> to observe the system again over the next year, but they also requested time with the more powerful James Webb Space Telescope, which could provide more clues about the existence or features of the planet.\n <\/p>\n \n If confirmed, this distant world would belong to an entirely new planetary class and suggest that more second-generation planets could exist around white dwarfs, Williams said.\n <\/p>\n \n The discovery would also have implications for our own cosmic neighborhood, Wilson said. \u201cThe sun will eventually become a white dwarf, so we\u2019re also looking at the future of the solar system here \u2014 maybe the Sun will get a new planet someday!\u201d\n <\/p>\n \n The new discovery of a potential second-generation planet is incredibly exciting, said Sarah Casewell, a lecturer at the School of Physics and Astronomy of the University of Leicester, England, who was not involved with the study.\n <\/p>\n \n \u201cWe know of a large number of white dwarfs that are polluted by planetary material which is similar in composition to rocks within our solar system,\u201d she wrote in an email. \u201cHowever, in this case, the white dwarf is polluted by incredibly unusual material and the composition of this material is similar to atoms we see being created as stars end their lives.\u201d\n <\/p>\n \n More than 95%<\/a> of all stars in the universe will eventually become white dwarfs, and astronomers have already cataloged hundreds of thousands<\/a> of them. Finding a planet that has formed after the white dwarf would mean that second-generation planets around other white dwarfs are possible \u2014 and that after our sun dies, new planets could emerge in our own solar system, Casewell said.\n <\/p>\n![\"An](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/10\/jpegpia16885.jpg\")
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