astronomers have photographed a planet that is six times as massive as Jupiter and one of the Sonnen -naves circles stars. It is the first

"This is a cold planet," says astronomer Elisabeth Matthews from the Max Planck Institute for Astronomy in Heidelberg, Germany. The results were published on July 24th in Nature 1

"If it is real, the planet is by far the oldest and coldest that has ever been shown," says Markus Janson, an astronomer at the University of Stockholm.

researchers usually discover exoplanets by pursuing how they cross the line of sight to earth periodically, temporarily dim the light of their host stars or because their gravitational effect causes a measurable wobble in the star itself. So far, only a few dozen exoplanets directly mapped , typically because they are hot and bright enough to be recognizable despite the gloss of your stars.

With the help of 'Wobble' techniques, astronomers had already seen indications that a massive object could move around the sun-like star ε indi a, which is only 3.6 parsecs (12 light years) from the earth in the distant constellation.

To search for a planet, Matthews and her employees organized the telescope so that the star was exactly in the center of their field of vision. Then they used the "coronograph" function integrated in one of the cameras of the WebB. The instrument can capture photons in slightly different times or phases in each of the four quadrants of its image frame. In this way, when the sensor data were combined, photons from ε indi a itself - of which some deviate from the center - were largely neutralized, which removed the shine that would have drowned any other signal in the vicinity of the star.

artistic representation of a cold gas giant in an orbit around a red dwarf.

The resulting picture revealed a planet that is six times as heavy as Jupiter, which means that, like Jupiter, it must be a "gas giant" that mainly consists of hydrogen gas, says Matthews. The planet, called ε indi, is about 15 times as far from its host star as the earth from the sun, and its temperature is just over 0 ° C.

Janson warns that "the egg -laying wool milk sow to evidence that it is definitely a planet" - a later picture that shows that the light point has moved - does not yet exist. But, he adds, "the study is of great, great importance because it is a step towards ability to map planets in mature systems". Previous direct imaging efforts were limited, he says, to observe young star systems, while ε indi a is almost as old as the sun. ”

Matthews says that your team is planning follow -up observations to measure the light spectrum of the planet. This could also reveal some of the components of its atmosphere, which would provide information on where and how such a large planet in the primeval fog, in which ε indi a was created, could have arisen.

The star forms a triple system together with two "brown dwarfs" objects that never became big enough to trigger a hydrogen fusion in their nuclei - which circle more than 1,000 times further from the superjupiter. "It is a really unusual type of system that we are really lucky to have in our back yard," says Matthews.