It is an example of what astronomers call an “interstellar planet.” It is believed that some are “born” like normal planets, but leave their stars after colliding with another object that sends them into flight, into space, like a billiard ball.
Other interstellar planets can also form when clouds of gas and dust implode to form a planet rather than a star. “The universe could be full of such planets, and we wouldn’t even know it,” said Scott Gaudi, a professor of astronomy at Ohio State University who helped discover the new planet. communique al NASA.
The interstellar planet turned out to be about the mass of Earth or Mars
What makes the planets extremely difficult to observe is that they are very faint, because there are no stars nearby to illuminate them. That is why only a few of these planets have been discovered so far. Even more difficult to identify is the fact that they tend to be very cold, which means that they do not appear on infrared telescopes.
To identify the latest interstellar planet, Gaudi’s team used a new technique called “microlensation”, as detailed in the process in a work in arXiv. The technique observes the changes of deformation that the mass has on the space-time concept.
Basically, when an interstellar planet moves in front of a more distant star, the star’s light bends around the planet from our point of view, as it passes through the deformed fabric of space-time near the planet. The more massive the planet, the more extreme the effect.
The team used NASA’s Nancy Grace Roman Space Telescope to observe the lone planet – a feat that would have been impossible without the specialized telescope, according to the team behind the discovery.
“The microlensation signal from an interstellar planet lasts only a few hours to a few days and then disappears forever,” Matthew Penny, an assistant professor of physics and astronomy at Louisiana State University and co-author of the paper, said in a statement. NASA statement. “This makes them difficult to observe from Earth, even with multiple telescopes. But the Roman telescope is a game changer for interstellar planet searches. “
The Roman Telescope is designed to hunt these interstellar planets and see how common they are. Such a discovery could influence the way we understand the formation and evolution of planets. “We would never know without undertaking a detailed, space-based microlensing process, as Roman will,” Gaudi added.