Is there life after death?<\/p>\n
For star systems, the answer seems to be yes. Astronomers have identified the first strong hints of a newborn planet orbiting a white dwarf, which is a remnant of a star like our Sun after it has exhausted its nuclear fuel. In a cruel irony for the planet, the hints of its existence come from the white dwarf actively eating its progeny\u2019s atmosphere. But for astronomers, it\u2019s an exciting possibility.<\/p>\n
On the basis of the strange chemical composition of the white dwarf atmosphere, the new exoplanet candidate seems to be a second-generation planet<\/a>, formed out of the debris shed by the dying star rather than the debris shed by its birth.<\/p>\n \u201cThis white dwarf is unique because it has a lot of traces of copper, zinc, and niobium,\u201d said Jamie Williams<\/a>, an astronomer at the University of Warwick in the United Kingdom who was the lead author of the study, published in Nature Astronomy. \u201cNiobium is especially interesting [because] that\u2019s the first time it\u2019s ever been discovered in a white dwarf.\u201d<\/p>\n \u201cI don\u2019t know of any other source that comes close to being this strange.\u201d<\/p>\n When astronomers see chemical elements heavier than hydrogen and helium in a white dwarf\u2019s atmosphere, it\u2019s likely \u201cpollution\u201d from a planet. The planet might have been destroyed when the star died\u2014Earth\u2019s possible fate when our own Sun goes kerplooie in 5 billion years or so\u2014or might be a survivor from the original star system.<\/p>\n \u201cI don\u2019t know of any other source that comes close to being this strange,\u201d said Juliette Becker<\/a>, a planetary astronomer at the University of Wisconsin\u2013Madison who was not involved with the study. \u201cThis [white dwarf] is very different from pollution profiles that have existed so far, which is very exciting.\u201d<\/p>\n Cookie Monster Devouring His Children<\/p>\n Like all stellar corpses, white dwarfs are weird objects. This particular example, which carries the memorable name HS 0209+0832, is probably about half the mass of the Sun but the size of Earth, measurements that are fairly typical for a white dwarf. However, HS 0209 is relatively newly formed and very hot: about 35,000 kelvin (~63,000\u00b0F), compared to the Sun\u2019s 5,800 kelvin surface temperature (10,000\u00b0F). A more fitting name might be \u201cultraviolet dwarf\u201d since its spectrum peaks in the UV.<\/p>\n When astronomers observed HS 0209 in 1999 using the Hubble Space Telescope<\/a>, they identified a relative excess of helium in its atmosphere. The amount came as a surprise because a white dwarf this hot should have little atmospheric helium. The new study drew together additional observations from a wealth of other telescopes, including later Hubble data, the Far Ultraviolet Spectroscopic Explorer (FUSE)<\/a>, and the Transiting Exoplanet Survey Satellite (TESS)<\/a>.<\/p>\n These additional data turned up further unexpected elements, including 3 times the niobium abundance seen in the Sun\u2019s spectrum. When the researchers compared this spectrum to other polluted white dwarfs and solar system objects like comets and meteorites, they found no matches: HS 0209 is unique. However, because astronomers think atmospheric pollution comes from material stripped from orbiting planets, it seemed possible that was the case here. That\u2019s where the TESS data, which measure fluctuations in the visible light output from stars, came in handy.<\/p>\n \u201cWe also see a variability in the brightness of the system, which we think is from a day-night phase curve of the planet around it,\u201d Williams said. In other words, as the hypothetical planet orbits, the total light from the system varies on the basis of which side of the planet is facing Earth on a 4.4-day orbital period, a type of planet known as a \u201chot Jupiter.\u201d<\/a><\/p>\n These data together indicate a planet whose chemistry corresponds to the very end stages of life for the progenitor star before it died and formed the white dwarf. In the scenario the researchers think is most probable, the gas the original star shed\u2014containing zinc, copper, and niobium\u2014provided the raw material for a second-generation planet.<\/p>\n \u201cWe have a white dwarf orbited by a disk of this kind of material [from the dead star],\u201d Williams said. \u201cThis disk will fragment and then you\u2019ll form a planet.\u201d<\/p>\n But like Saturn devouring his children<\/a> in Greco-Roman mythology, the white dwarf began boiling off the newborn planet\u2019s atmosphere, absorbing part of the planetary atmosphere into its own and shedding most of the rest into space. (Perhaps Cookie Monster<\/a>, with his messy eating habits, is a better metaphor.) This merging explains not only the excess of helium in HS 0209+0832\u2019s atmosphere but also the presence of elements that are rare in the solar system. Williams expressed a hope of using the James Webb Space Telescope<\/a> to attempt to directly detect the planet, which is hot enough to glow in the infrared.<\/p>\n \u201cBecause there are [pulsar] second-generation planets, I think there must be also second-generation planets around white dwarfs.\u201d<\/p>\n Both Williams and Becker pointed out that HS 0209, pollution aside, is a very typical white dwarf, meaning it\u2019s possible many other second-generation planets could be out there. Becker, who studies unusual scenarios for planetary formation, noted that second-generation planets were actually the first exoplanets discovered. However, those were orbiting pulsars<\/a>: the remnants of stars many times more massive than our Sun.<\/p>\n \u201cI also have a strong bias: Because there are [pulsar] second-generation planets, I think there must be also second-generation planets around white dwarfs,\u201d she said.<\/p>\n \u2014Matthew R. Francis (@BowlerHatScience.org<\/a>), Science Writer<\/p>\n Citation:\u00a0Francis, M. R. (2026), White dwarf spotted devouring the planet it birthed,\u00a0Eos, 107, https:\/\/doi.org\/10.1029\/2026EO260329. Published on 20 October 2026.<\/p>\n