In a galactic first, the star swallows the planet in one gulp
CAPE CANAVERAL, Fla. (AP) — For the first time, scientists have caught a star gobbling up a planet — not just a nibble or bite, but a big gulp.
Astronomers on Wednesday reported their observations of a gas giant the size of Jupiter or larger being eaten by its star. The sun-like star had swelled with eons of old age, eventually growing so large that it engulfed the nearby planet.
It’s a bleak preview of what will happen to Earth as our sun transforms into a red giant and engulfs the four inner planets.
“If it’s any consolation, it’s going to happen in about 5 billion years,” said co-author Morgan MacLeod of the Harvard-Smithsonian Center for Astrophysics.
This galactic festival took place near the constellation Aquila 10,000 to 15,000 years ago, when the star was about 10 billion years old. As the planet descended the stargate, there was a rapid hot burst of light, followed by a long-lasting dust stream that glowed brightly with cold infrared energy, the researchers said.
While there had previously been signs of other stars munching on planets and their digestive aftermath, this was the first time the swallow itself had been observed, according to the study, published in the journal Nature.
Massachusetts Institute of Technology researcher Kishalay De spotted the 2020 flare while reviewing sky scans taken by the California Institute of Technology’s Palomar Observatory. It took additional observations and data processing to unravel the mystery: instead of a star devouring its companion, it had devoured its planet.
Given a star’s lifespan of billions of years, the swallow itself was fairly brief — it essentially happened in one fell swoop, said Mansi Kasliwal of Caltech, who was part of the study.
The results are “very plausible,” said Carole Haswell, an astrophysicist at Britain’s Open University who was not involved with the research. In 2010, Haswell led a team that used the Hubble Space Telescope to identify the star WASP-12 as it engulfed its planet.
“It’s a different way of eating. This star swallowed an entire planet in one go,” Haswell said in an email. “In contrast, WASP-12 b and the other hot Jupiters we’ve previously studied are delicately licked and nibbled.”
Astronomers do not know if there are other planets orbiting this star at a safe distance. If so, De said, they could have thousands of years before becoming the star’s second or third course.
Now that they know what to look for, researchers will keep an eye out for more cosmic gulps. They suspect that thousands of planets around other stars will suffer the same fate as this one and eventually our solar system.
“Everything we see around us, all the stuff we’ve built around us, it’s all going to be gone in an instant,” De said.
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