An illustration from the European Southern Observatory depicts the exoplanet Proxima Centauri b, the closest exoplanet to the sun. A new study by astronomers using the ESO identifies the faintest exoplanet ever imaged from Earth. File Photo by M. Kornmesser/European Southern Observatory
July 15 (UPI) — A team of astronomers found a new exoplanet — the faintest ever imaged from the ground — hiding in plain sight in images that date back at least 11 years, a study released Wednesday in The Astrophysical Journal Letters said.
Ben Sutlieff, an astronomer at the University of Edinburgh and co-lead of the study, called the discovery a “serendipitous” one.
Sutlieff said the team initially wanted to look at a known planet orbiting the star Beta Pictoris, using the European Southern Observatory’s Very Large Telescope and seeing how it changed over time. When they analyzed their images, however, they found another planet, one previously unknown.
“There’s something else there; did you see it?” Markus Bonse, the other co-lead of the study, remembered saying. The group looked through the ESO archive and found the new planet in images going back at least 11 years. In one image, it was barely visible against Beta Pictoris’ first-known planet, called Beta Pictoris b.
The new planet is called Beta Pictoris d.
“Planet d, it seems, has been playing a game of hide-and-seek with us for over a decade,” said Jayne Birkby, co-author of the study and an astronomer at the University of Oxford.
Beta Pictoris d is 63 light-years away from Earth. It’s a gas giant, as are the two other planets in its solar system, as well as Jupiter and Saturn in our system. It has a much wider orbit than Beta Pictoris b and Beta Pictoris c.
It’s unusual — as well as difficult — to take a direct image of a planet as faint as Beta Pictoris d. Direct imaging captures the light from an object, so it only works with planets that show up next to their (much brighter) stars. Bonse said the new planet is 100 times fainter than Beta Pictoris b.
Another team, this one led by Aiden Gibbs of the University of California in the United States also discovered Beta Pictoris d using the James Webb Space Telescope. The Astrophysical Journal Letters also had their results today.
