On Tatooine, Luke Skywalker’s home planet, two suns rose and set everyday. Astronomers have confirmed that Tatooine is not the only one. There re many more planets out there who rotate around twin stars.
Kepler-34 b which was found a few months ago is about 22 percent of the mass and 76 percent the width of Jupiter. The planet is about 4,900 light-years from Earth.
Kepler-35 b orbits two stars 5,400 light-years from Earth. It has about 13 percent the mass of and is 73 percent as wide as Jupiter.
What makes both these planets interesting is they are right in the middle of the star’s habitable zone. This is the distance from a star where it is not too hot or too cold for liquid water to form and thereby could support life.
William Welsh, from San Diego State University and the lead on this study, told SPACE.com
“With only three circumbinary [dual star] planets known, we are already very close to that special ‘Goldilocks’ zone. It is my opinion that circumbinary planets in the habitable zone will turn out to be fairly common, and that is exciting.”
Welsh went on to describe how the planets need to be in a perfect area otherwise the gravity of two stars could make orbits erratic. He said,
“If they were only 20 to 25 percent closer to their stars, the gravitational tugs of the two stars would build up over time and eventually make the planet’s orbit so wild that the planet would be ejected into deep space.”
The fact that three of these systems have been found this year alone points out that there could be millions of them. There is one found only 200 light years away.