"This is something astronomers were not convinced about, even as little as five years ago.
"These new planets also help us better understand the formation processes of planetary systems and provide interesting targets for future efforts to image the planets directly."
The observations were part of the Lick-Carnegie Exoplanet Survey, which was started in 1996 by astronomers Steve Vogt and Geoffrey Marcy from the University of California and Paul Butler, from the Carnegie Institute of Science, in Washington.
