Find a Super-Earth in a planetary system, it's good for astronomers. But find 3 Super-Earths for the same star, it's the jackpot for the European Southern Observatory. And where ? In the triple-star system Gliese 667, in particular in Gliese 667C.
Located at 22 light-years from the Sun, Gliese 667C, a red dwarf 5 times smaller than the Sun, is a great candidate for exoplanets search. The 3 planets we know in this system orbit at a distance from 7 to 36 million kilometers from the star. The most surprising is that Gliese 667Cb, Cc et Cd are all three in the habitable zone. So these planets would contain water and rock. According to ESO, they are more massive than the Earth but less massive than Neptune and Uranus.
"This is the first time that 3 planets of this type have been identified in this area of a same system", announced the Observatory.
However, the search in Gliese 667C wouldn't stop here. By confirming the existence of the 3 planets, astronomers probably discovered the existence of 2 other planets, Gl-667Ce and Cf, which are currently not confirmed.
Rock planets, 5 planets in a same system ... we can now ask this question : Is Gliese 667C system a cousin of our solar system ?
Sources : ESO, Le Huffington Post (article in french)