“Our new observations with HARPS mean that about 40% of all red dwarfs have a super-Earth orbiting in their habitable zone where liquid water can exist on the surface of the planet,” said Xavier Bonfils (IPAG Observatory Sciences of the Universe, Grenoble, France), the team leader. “The fact that red dwarfs are so common – there are about 160 billion in the Milky Way has led us to wonder result that there are tens of billions of such planets in our galaxy alone. ”
By combining all data, including observations of stars that have no planet, and looking at the fraction of existing planets that could be discovered, astronomers have determined that the frequency of the presence of super-Earths in the habitable zone is 41% with a margin ranging from 28% to 95%. Moreover, the most massive planets, like Jupiter and Saturn in our Solar System, proved to be rare around red dwarfs.