Astronomers may have discovered the lightest exoplanet ever seen, which appears just as a dot orbiting a young star.
The newly-discovered planet orbits the young star HD 95086 at a distance of around 56 times the distance from the Earth to the Sun, twice the Sun-Neptune distance.
Although nearly a thousand exoplanets have been detected indirectly — most using the radial velocity or transit methods — and many more candidates await confirmation, only a dozen exoplanets have been directly imaged.
ESO’s Very Large Telescope captured on camera what is probably the lightest of these objects so far.
“Direct imaging of planets is an extremely challenging technique that requires the most advanced instruments, whether ground-based or in space,” said Julien Rameau from Institut de Planetologie et d’Astrophysique de Grenoble, France.
“Only a few planets have been directly observed so far, making every single discovery an important milestone on the road to understanding giant planets and how they form,” said Mr. Rameau.
The likely planet appears as a faint but clear dot close to the star HD 95086. A later observation also showed that it was slowly moving along with the star across the sky.
This suggests that the object, which has been designated HD 95086 b, is in orbit around the star. Its brightness also indicates that it has a predicted mass of only four to five times that of Jupiter.
The observations were made using infrared light and a technique called differential imaging, which improves the contrast between the planet and dazzling host star.
The youth of this star, just 10 to 17 million years, leads astronomers to believe that this new planet probably formed within the gaseous and dusty disc that surrounds the star.
