Gliese 667 is a triple star system about 22 light years from Earth in the constellation of Scorpius. Two of these stars–Gliese 667 A and B–are Sun-like and orbit each other relatively closely.
The third is much more interesting. Gliese 667C a red dwarf that is about a third of the mass of our Sun and only about 1 per cent as bright. It orbits the other two stars at a much greater distance: some 200 astronomical units or about 30 billion kilometres.
Red dwarfs are particularly interesting for astronomers because their small mass makes it much easier to spot orbiting planets. What’s more, their low luminosity means that these stars’ habitable zones are much closer than for brighter stars.
Since current planet spotting techniques favour closer planets, astronomers know they are much more likely to find planets in the habitable zone around red dwarfs. In fact, today’s news is a good example.
Today, Philip Gregory at the University of British Columbia in Canada says that Gliese 667Chas three planets sitting squarely in the middle of its habitable zone.To read more, click here.