Scientists have finally spotted the dimmest planet ever seen from Earth – after more than a decade.
The faint, elusive world orbits a young star. It had been lying undiscovered in existing data for 11 years, but was hidden in the bright light of its star and two companion worlds.
The planet was found, separately, by two teams just a few days apart, last year.
A Scottish and German-led team spied the new planet around the star Beta Pictoris using the European Southern Observatory's Very Large Telescope in Chile, then dug through archives to confirm its orbit. The planet had remained hidden in the data all this time, overshadowed by its considerably brighter star and two companion planets.
“It was very much playing hide-and-seek for 11 years,” said the European Southern Observatory's Markus Bonse, co-leader of the first team.
The California-led team made the discovery with NASA's Webb Space Telescope. Two observations were all it took with Webb, the biggest and most powerful telescope ever launched into space. Both teams reported their findings in the Astrophysical Journal Letters.
The find was serendipitous. Each team was studying one of the star's already identified planets when they spotted a less massive one — 100 times fainter — lurking farther out. They deliberately kept their work from one another so as not to bias the results.
The new planet is slightly bigger than Jupiter and takes 91 years to orbit its star, a little longer than it takes Uranus to orbit our sun. Born into a star system that's barely 20 million years old — a kid compared to the sun's 4.5 billion-year-old neighborhood — the planet is probably similar to a much younger Jupiter, said the University of California San Diego's Aidan Gibbs, who led the second team.
“The giant planets have formed, but smaller terrestrial planets could still be forming,” Gibbs said in an email. Beta Pictoris “is probably our best look at a planetary system just after it has formed and is still in the process of stabilizing” from hurtling asteroids and comets.
Beta Pictoris is located in the easel-shaped southern constellation Pictor, or painter, and 63 light-years from Earth. A light-year is nearly 6 trillion miles (more than 9 trillion kilometers).
Fewer than 100 of the more than 6,000 confirmed exoplanets — planets around other stars — have been detected through direct imaging, according to Nasa. Most were found while passing in front of their star, briefly dimming it.
“We've now built a picture of this planet,” the University of Edinburgh's Ben Sutlieff said in an email, “and we are very excited to see what more can be learned about it.”
Additional reporting by agencies
