Photographed the lightest exoplanet so far - The País.com (Spain)

Almost a thousand planets have already been discovered outside our solar system, but the vast majority of them have been detected indirectly, is that astronomers have seen. Finding a comparatively dark object orbiting another star is bright as a challenge hard to only achieved with the best instruments of observation. Thus, only a dozen extrasolar planets had been imaged. The European Southern Observatory (ESO) reports today of a new one that also has four or five times the mass of Jupiter, may be the lightest of the photographed so far.

The planet, which in the images appears as a single point of light dim, called HD95086b and revolves around a star more massive than the Sun, much younger (10 to 17 million years, compared to 5,000 million from the central star of the solar system) and a disk of gas and matter around, is about 300 light years from Earth (the closest stars to the Solar System is just over four light-years). The planet orbits its star at about twice the orbit of Neptune, or about 56 times the distance from Earth to the Sun The brightness of the star has allowed astronomers to estimate the temperature of the planet at about 700 degrees Celsius . “It’s cold enough for there to be water vapor and methane in its atmosphere,” says Gael Chauvin, one of the authors of the finding. Another previously photographed extrasolar planet, Fomalhaut B may be lighter than HD95086b, but its mass has not been defined precisely, remember the ESO in a statement.

“The direct imaging of planets requires an extremely difficult technique that requires the most advanced instruments, whether on earth or in space,” says Julien Rameau (Institute of Planetology and Astrophysics of Grenoble, France), leading the team that made the discovery that disclosed in the journal Astrophysical Journal Letters . “Only a few planets have been directly observed so far, which makes each finding be an important milestone in the path of understanding and how giant planets form,” he adds.

first extrasolar planet was discovered in 1995 by Michel Mayor and Didier Queloz (Geneva Observatory both) by an indirect technique tuned by them: measure the slight wobble when suffering a star has a planet (or several) turning around. It’s like watching a giant spinning round a little boy gripped by hands, so that, although not seen the child, adult movement reveals its presence. This method has discovered many of the extrasolar planets. Another successful technique, thoroughly exploited by the Kepler telescope U.S. , is called traffic. What astronomers do in this case is extremely light measuring star brightness dimming when a planet crosses in front of him in the line of sight from Earth, as a partial minieclipse. It is also, therefore, an indirect technique.

To shoot the HD95086b, astronomers have used one of the big four VLT telescopes, the ESO and located in Chile, with advanced camera NACO, thanks to a technique called adaptive optics, allows combat blur in the images due to the Earth’s atmosphere and provides some extremely sharp results. They have made infrared observations.