Not one, but three planets found in Gliese 667C’s habitable zone
Scientists using data from the ESO’s
HARPS (High Accuracy Radial velocity
Planet Searcher) have discovered not one, but three super-Earths orbiting in the stellar habitable zone of Gliese
667C. It’s a record-breaker as far as finding planets where liquid water might exist is concerned, and it means that this habitable zone is as populated with planets as it can get.
“We knew that the star had three planets from previous studies, so we wanted to see whether there were any more,” said Mikko Tuomi, one of the astronomers from the University of
Hertfordshire. “By adding some new observations and revisiting existing data we were able to confirm these three and reveal several more. Finding three low-mass planets in the star’s habitable zone is very exciting!”
Gliese 667C itself is relatively close to the Solar System at 22 light years away. This makes it easier to observe and the team has already confirmed at least six planets around the star with a possible seventh, making this system a reasonably close analogue to the Solar System. Gliese 667C is part of a triple-star system with the three super-Earths orbiting one of the fainter stars and the other two stars providing as much light during the night as a full Moon on Earth.
Super-Earths are simply defined as planets orbiting in a star’s habitable zone that are more massive than
Earth and less massive than planets like Neptune or Uranus.