Science. New technology to search for exoplanets discovers worlds we can see

Madrid, 14 (Europe Press)

Its application resulted in a direct image of a Jupiter-like gas giant located 132.8 light-years away in the constellation Cygnus. The result is reported in Science.

The planet, called HIP 99770 b, is the first planet outside our solar system to be found using a powerful combination of astrometry and direct imaging.

Two observatories from Maunakea on the island of Hawaii, the WM Keck Observatory and the Subaru Telescope, have performed direct images, directly capturing infrared images of the planet. The astrometry, which measured the position and motion of HIP 99770 b’s source star, came from the European Space Agency’s Gaia Space Observatory and its predecessor, Hipparcos.

“Direct imaging and astrometry allow us to gain a complete understanding of an exoplanet for the first time: measure its atmosphere, weigh it, and track its orbit, all at the same time,” said Thayne Currie, Subaru Telescope researcher and study leader. . “This new approach to finding planets is foreshadowing how we might one day identify and characterize Earth’s twin around a nearby star.”

HIP 99770 b is difficult to detect; Because the planet is opaque, it can get lost in the glow of its bright host star.

“This is the kind of discovery that could only have been made from Maunakea,” Currie said. “We are very grateful for being given the privilege of studying the sky from this mountain.”

This new method of combing for nearby exoplanets is a major improvement over traditional terrestrial means; Over the past 14 years, astronomers have used so-called “blind” surveys to scan the skies for stars that show potential for hosting giant planets that we can image directly from Earth based on their age and distance from the planet. star system. However, this method has poor performance. Accurate astrometry, on the other hand, detects the motion of stars, allowing researchers to focus on those that are being pulled by the gravitational pull of an unseen companion, such as a planet, and then take a picture of star systems that are close enough. to get a direct picture.

“Our discovery really changes the way we do exoplanet science,” Currie said. “Direct imaging is very exciting but also a real challenge, as we spent many nights looking for planets around other stars from many programs only to find gaps. By fine-tuning our technique with astrometry, we now know exactly where to look.”