ESO Very Large Telescope Directly Captures Image of Lightest Alien Planet Yet

ESO's Very Large Telescope has captured an amazing image. It's discovered a very faint object moving near a bright star. With an estimated mass of four to five times that of Jupiter, this object could be the lightest alien planet to be directly observed outside the Solar System yet.

So far, nearly a thousand exoplanets have been detected indirectly using techniques such as radial velocity or transit methods. In fact, many more await confirmation. Despite the many planets that have been imaged indirectly, though, only about a dozen have been detected directly.

"Direct imaging of planets is an extremely challenging technique that requires the most advanced instruments, whether ground-based or in space," said Julien Rameau, first author of the paper detailing the discovering, in a news release. "Only a few planets have been directly observed so far, making every single discovery an important milestone of the road to understanding giant planets and how they form."

The latest exoplanet that was imaged is probably the planetary companion to a star called HD 95086. Now named HD 95086 b, the exoplanet was seen slowly moving along with the star across the sky. Extremely bright in comparison to other planets, researchers estimate that it's probably about four to five times the size of Jupiter--relatively small when it comes to supermassive planets.

In order to actually directly image this exoplanet, though, the researchers had to use NACO, the adaptive optics instrument mounted on one of the Unit Telescopes of the Very Large Telescope (VLT). The instrument allowed the astronomers to remove most of the blurring effects of the atmosphere and obtain very sharp images. Using infrared light and a technique called differential imaging, the researchers were able to improve the contrast between the planet and the host star. This, in turn, allowed them to directly detect the exoplanet.

The newly discovered planet orbits its host star at around 56 times the distance from Earth to the Sun--that's twice the Sun-Neptune distance. The star itself is slightly more massive than our own Sun and is surrounded by a debris disc and lies about 300 light-years away from Earth.

"Its current location raises questions about its formation process," said Anne-Marie Lagrange, one of the team members, in a news release. "It either grew by assembling the rocks that form the solid core and then slowly accumulated gas from the environment to form the heavy atmosphere, or started forming from a gaseous clump that arose from the gravitational instabilities in the disc."

Currently, researchers are planning to continue studying this exoplanet and its star in order to learn more about it. More specifically, astronomers hope to use VLT's forthcoming SPHERE instrument in order to determine whether or not water vapor and methane exist in the planet's atmosphere.

Want to see another image of the exoplanet? Check it out here.

The findings are published in The Astrophysical Journal Letters.