A white dwarf star that some media outlets have taken to calling a real-life Star Wars “Death Star” has been caught cannibalizing the small, rocky remains of a planet that once inhabited its solar system, NASA officials announced on Wednesday.
The discovery, made by scientists using the US space agency’s Kepler space telescope (known as the K2 mission), confirms a long-held theory that white dwarfs are capable of consuming the asteroid-sized remains of a one-time planet, disintegrating it while it orbits nearby.
In research published in the latest edition of the journal Nature, the researchers reveal that this activity is occurring around a white dwarf approximately 570 light years away. The planet is in orbit around the dying star at a distance about twice that separating the Earth and the Moon.
It’s this proximity, The Washington Post explained, that is causing the rocky mass to be put in peril. The remnant planet was observed while it was transiting (passing in front of) its host star, and the pattern of dimming detected by Kepler revealed that the object was shaped like a comet with a tail—likely debris from the object being pulled apart by the dense star’s gravity.
The ‘smoking gun’ linking white dwarfs to planet destruction
The object and its star were originally detected by Kepler during its first observational campaign, which lasted from May 30, 2014 to Aug. 21, 2014. They discovered a significant decrease in the brightness that occurred once every 4 1/2 hours, as the transiting object blocked up to 40 percent of white dwarf’s light. Its pattern of transit, however, revealed its unusual shape.
The planetary remnant showed an asymmetric elongated slope pattern indicative of its comet-like tail. Their observations led them to conclude that there was a ring of debris encircling the star, as well as the telltale signs of a small rocky object being disintegrated. Ground-based observations conducted at the University of Arizona’s MMT Observatory later confirmed their findings.
“This is something no human has seen before. We’re watching a solar system get destroyed,” lead author, Andrew Vanderburg from the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, said in a statement. He added that the discovery was the “smoking gun” linking white dwarfs polluted by heavy metals to “the destruction of rocky planets.”
“For the last decade we’ve suspected that white dwarf stars were feeding on the remains of rocky objects, and this result may be the smoking gun we’re looking for,” said K2 staff scientist Fergal Mullally from SETI and NASA’s Ames Research Center in Moffett Field, California. “However, there’s still a lot more work to be done figuring out the history of this system.”
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Feature Image: CfA/Mark A. Garlick
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