Astronomers Capture the Moment a Star Expands and Eats One of Its Orbiting Planets
In a few billion years our Sun is going to go caput, but as that happens, it’s actually going to expand and engulf several planets. But while that’s a long way off, astronomers were able to finally see that phenomenon happening in another star system.
Just in time for Star Wars Day, astronomers for the first time Wednesday announced the discovery of a “Death Star” destroying a distant planet, a sight that could be a preview of Earth’s eventual destiny.
The sun-like star, known as ZTF SLRN-2020, lies about 15,000 light-years away in our own Milky Way galaxy in the constellation Aquila and is thought to have engulfed a hot-gas giant planet about the size of Jupiter.
“The confirmation that sun-like stars engulf inner planets provides us with a missing link in our understanding of the fates of solar systems, including our own,” said Kishalay De, a postdoctoral scholar at MIT and lead author of a new study that appears in the peer-reviewed British journal Nature.
Five billion years from now, it’ll happen to Earth
Some five billion years from now, when our sun is expected to become a red giant, swallowing up Mercury, Venus and possibly Earth, the light show should be much more subdued, according to De, since those planets are many times smaller than the Jupiter-size planet featured in the new study.
“We are seeing the future of the Earth,” De says. “If some other civilization was observing us from 10,000 light-years away while the sun was engulfing the Earth, they would see the sun suddenly brighten as it ejects some material, then form dust around it, before settling back to what it was.”
A galactic feast
This galactic feast happened between 10,000 and 15,000 years ago when the star was around 10 billion years old. As the planet went down the stellar hatch, there was a swift, hot outburst of light, followed by a long-lasting stream of dust shining brightly in cold, infrared energy, the researchers said.
While there had been previous signs of other stars nibbling at planets and their digestive aftermath, this was the first time the swallow itself was observed.
Astronomers used a combination of telescopes to spot the first direct evidence of the aging, bloated sun-like star, engulfing its planet.
The star was first spotted by the Zwicky Transient Facility, or ZTF, an instrument that scans the skies every night from the Palomar Observatory near San Diego.
The Nature study titled, “An infrared transient from a star engulfing a planet,” was funded by NASA, the National Science Foundation, and the Heising-Simons Foundation.
Contributing: The Associated Press