Astronomers in Germany have announced the discovery of three planets in a star system some twenty-two light years from Earth. The exoplanets, which are all believed to be rocky super-earths, orbit their host star in the so-called “Goldilocks” zone – where the temperature is not too hot and not too cold — meaning they may be capable of sustaining organic life, astronomers say.
The planets were discovered in a solar system which bears similarities to our own, astronomers at the University of Gottingen revealed. Between five and seven planets orbit Gliese 677C star – part of a trinary system called Gliese 667.
“We identified three strong signals in the star before, but it was possible that smaller planets were hidden in the data. We re-examined the existing data, added some new observations, and applied two different data analysis methods especially designed to deal with multi-planet signal detection,” commented Guillem Anglada-Escude, who led the initiative.
“Both methods yielded the same answer: there are five very secure signals and up to seven low-mass planets in short-period orbits around the star,” he continued.
The Gliese 667C system is unique as it is the first solar system discovered with more than one planet orbiting within its star’s habitable zone. In our own solar system the Earth is the only planet within the Sun’s “Goldilocks” zone, with Venus and Mars orbiting marginally outside.
The host star in the Gliese 997C system is just one-third the mass of our Sun, making the discovery of three planets within its habitable zone all the more impressive.
The newly discovered planets lie in the constellation Scorpius – which, at twenty-two light years away, is right in Earth’s cosmic back garden, and much closer than the stars being scanned by Nasa’s advanced Keplar telescope.
The discovery came about after scientists peering through the European Southern Observatory’s Very Large Telescope took another look at the Gliese 667 system, where they had already discovered three planets outside the host star’s habitable zone.
The discovery of the three new planets may mean that more habitable planets occupy the Milky Way than first thought.