An unnamed exoplanet formed from the remnants of a dying star — a phoenix planet — has been found circling a white dwarf for the first time, according to a study published in the journal Nature Astronomy. White dwarfs are created when stars “exhaust the hydrogen in their cores needed to fuel nuclear fusion,” said Space.com.
The atmosphere of this white dwarf, HS 0209+0832, had an “unusual chemical signature” with “oddly heavy elements including zinc, copper and, most notably, niobium,” that are “created during the death of a star,” the European Research Council said in a news release. This signature is likely the white dwarf “feeding off a newly formed second-generation giant planet” that “condensed out of a new disc of material formed during the star’s death.” Scientists suspect that the atmosphere of the phoenix planet is “being stripped by the white dwarf’s stellar winds, causing the rare elements to fall back onto the zombie star,” said Live Science.
There may be more phoenix planets circling white dwarfs. “Over 95% of stars in the Milky Way will evolve to become a white dwarf,” said lead study author Jamie Williams to Reuters. In the future, our own solar system could “host a second-generation planet formed from the ashes of our sun,” the ERC said.
While this is a gas planet, other phoenix planets could be rocky or even hold life. White dwarfs “cool predictably over time,” said Williams. If a “second-generation rocky planet formed close enough to the white dwarf,” it could “remain in the habitable zone for billions of years.”
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