Scientists say they’ve detected a giant planet circling a star that’s only 5 million to 10 million years old, which would make it the youngest exoplanet ever identified.
The super-Neptune-sized planet traces a super-close-in orbit, making a complete swing around its parent star every 5.4 Earth days, according a team of astronomers associated with NASA’s repurposed Kepler space telescope. The star, known as K2-33, is in the Upper Scorpius stellar association, about 500 light-years from Earth.
Infrared observations of K2-33 indicate that the star is still surrounded by the remnants of gas and dust from a protoplanetary disk. Such disks form around stars as they’re born and give rise to planets, but the disks are thought to dissipate after a few million years. That’s how astronomers figured out that the planet was so young.
“At 4.5 billion years old, the Earth is a middle-aged planet — about 45 in human-years,” Caltech astronomer Trevor David said in a news release. “By comparison, the planet K2-33b would be an infant of only a few weeks old.”