Astronomers find evidence of potential second-generation planet around white dwarf star

Scientists have discovered evidence of a possible second-generation planet around a white dwarf star located approximately 270 light years from Earth. The findings, published in a study in Nature Astronomy, indicate that gases released from the dead star HS 0209+0832 have coalesced into a planet roughly the size of Jupiter. A team of UK-based scientists analyzed data from NASA’s Hubble Telescope collected in 1999 and identified around 100 unidentified chemical features surrounding the dense star, which is situated in the Milky Way and can be observed in the constellation Cetus. Researchers theorized that the presence of elements such as niobium and other heavier elements suggests that a planet formed from stellar material expelled by the dying white dwarf. This contrasts with the formation of most planets, including those in our solar system, which typically occur during the birth of a star. Dr. Nicholas Stone, a theoretical astrophysicist at the University of Wisconsin – Madison and co-author of the study, stated that these heavy elements can only be produced under the unique conditions present in dying stars. Additionally, scientists detected a repeating brightness cycle of approximately 4.4 days, which may correspond to the day and night temperature variations of a massive planet orbiting very close to its star, at 0.04 Astronomical Units, or 25 times closer than Earth is to the Sun. If the planet exists, it is losing atmosphere, but researchers remain optimistic about its potential for survival. Jamie Williams, an astronomer at the University of Warwick and co-author of the study, expressed confidence that if the second-generation planet is present, it is likely to endure. Williams noted that eventually, the white dwarf will cool and maintain a stable temperature, allowing the planet to remain in its habitable zone for millions of years. This stable temperature could enable a close-in rocky planet to remain habitable for tens of billions of years, significantly longer than Earth, which is expected to be engulfed or burned by the Sun within 5 billion years. However, experts emphasized that the existence of this first-ever second-generation planet has yet to be officially verified, and further research is necessary.