by CAPE CANAVERAL, Fla. (AP) — For the first time, scientists have caught a star in the act of swallowing a planet — not just a bite or a bite, but a big gulp.
Astronomers reported Wednesday their observations of what appeared to be a gas giant the size of Jupiter or larger being devoured by its star. The sun-like star had been swelling with old age for eons and eventually grew so large that it engulfed the planet in close orbit.
It’s a grim preview of what will happen to Earth when our sun turns into a red giant and engulfs the four inner planets.
“If it’s any consolation, that will happen in about 5 billion years,” said co-author Morgan MacLeod of the Harvard-Smithsonian Center for Astrophysics.
This galactic feast occurred between 10,000 and 15,000 years ago near the constellation Aquila, when the star was about 10 billion years old. As the planet descended from the stellar hatch, there was a rapid burst of hot light, followed by a long-lasting stream of dust that glowed brilliantly in cool infrared energy, the researchers said.
While there had been previous signs of other stars nipping at planets and their digestive consequences, this was the first time the swallow itself has been observed, according to the study appearing in the journal Nature.
Massachusetts Institute of Technology researcher Kishalay De spotted the bright burst in 2020 while examining scans of the sky made by the California Institute of Technology’s Palomar Observatory. It took further observations and data analysis to unravel the mystery: instead of a star devouring its companion star, it devoured its planet.
Given the life span of a star of billions of years, the swallow itself was quite short, essentially occurring 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 had no role in the research. Haswell led a team in 2010 that used the Hubble Space Telescope to identify the star WASP-12 in the process of consuming its planet.
“This is a different way to eat. This star swallowed an entire planet in one gulp,” Haswell said in an email. “By contrast, WASP-12b and other hot Jupiters we’ve studied previously are being licked and gnawed gently.”
Astronomers don’t know if more planets are circling this star at a safer distance. If so, De said it could be thousands of years before it becomes the second or third course of the star.
Now that they know what to look for, researchers will be on the lookout for more cosmic sips. They suspect that thousands of planets around other stars will suffer the same fate as this one, and eventually our solar system as well.
“Everything we see around us, everything we’ve built around us, will be gone in a flash,” De said.
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