Scientists added three new planets to three discovered in 2008 orbiting an orange star called HD 40307, which is roughly three-quarters as massive as the sun and located about 42 light-years away in the constellation Pictor.
Of particular interest is the outermost planet, which is believed to fly around its parent star over 320 days, a distance that places it within HD 40307’s so-called “habitable zone.”
“All we know at this point is that it has a minimum mass of about 7.1 Earth-masses. We have no explicit follow-up planned, thought the HARPS team is probably still gathering more data, and may in the future be able to confirm these results, and perhaps add even more planets to the brood,” astronomer Steven Vogt, with the University of California’s Lick Observatory, wrote in an email to Discovery News.
Based on our experience with other star systems this newly discovered planet is likely made of rock and may contain water. It receives 62 percent of the radiation from its star that Earth receives from the sun, but Earth is relatively near to the leading edge of the habitable zone.