The Hubble Space Telescope has spied a previously unknown exoplanet with similar properties as our Solar System's hypothetical object Planet Nine. This newly spotted body is living on the outskirts of another solar system 336 light-years away.
Astronomers have not yet glimpsed Planet Nine after it was predicted that the massive body may be orbiting our Sun on the outer edges of our Solar System. The evidence for such a planet could explain why the orbits of some distant Kuiper Belt objects beyond Neptune were so strange.
New readings from the Hubble Space Telescope point to just such a body orbiting a star 336 light years away. An exoplanet, dubbed HD 106906 b, has been tracked by a team of researchers led by those at the University of California, Berkeley, who analysed images taken over a 14-year period of the exoplanet to estimate its orbit.
"This system draws a potentially unique comparison with our solar system," said Meiji Nguyen, first author of a paper describing the finding, published this week in The Astronomical Journal, and a researcher at UC Berkeley.
“It's very widely separated from its host stars on an eccentric and highly misaligned orbit, just like the prediction for Planet Nine. This begs the question of how these planets formed and evolved to end up in their current configuration."
The planet has a mass eleven times that of Jupiter, and circles its parent twin stars at a distance of 68 billion miles away taking 15,000 years to complete its orbit. The astronomers believe HD 106906 b was once much closer to its host stars when it began forming 15 million years ago, about three times the distance Earth is from the Sun.
The drag within the protoplanet’s gas disk during its infancy, however, moved the exoplanet nearer the center of its solar system where the gravitational field from the binary stars forcefully booted it out towards space. It's theorized a passing star nudged it back towards its home and prevented the planet from escaping to outer space, with a very eccentric distant orbit.
The same thing may have happened to Planet Nine. "It's as if we have a time machine for our own planetary system going back 4.6 billion years to see what may have happened when our young solar system was dynamically active and everything was being jostled around and rearranged," said Paul Kalas, co-author of the paper and a lecturer at UC Berkeley.
The findings don’t confirm that Planet Nine exists, only that objects like it do elsewhere in space. Robert De Rosa, co-author of the paper and an astronomer at the European Southern Observatory, said NASA’s James Webb Telescope due to launch next year on Halloween could help uncover more similar oddball planets.
“One question you could ask," he said, "is: does the planet have its own debris system around it? Does it capture material every time it goes close to the host stars? And you'd be able to measure that with the thermal infrared data from Webb.” ®