The family of planets circling a relatively close dwarf star has grown to six, including a potential rocky world at least seven times more massive than Earth that is properly located for liquid water to exist on its surface, a condition believed to be necessary for life.
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.”
The planet’s five siblings are all believed to be too close to the star and therefore too hot for water to exist in a liquid state.
“The planetary system around HD 40307 has an architecture radically different from that of the solar system,” lead researchers Mikko Tuomi, with the University of Hertfordshire in the United Kingdom, and Guillem Anglada-Escude, with Germany’s University of Goettingen, write in a paper to be published in the journal Astronomy & Astrophysics.