The fictional Tatooine is a small and rocky celestial body but the real-life Kepler-1647b is a gas giant about the size and mass of Jupiter. The Kepler-1647b also has the widest orbit, circling its host stars in 1,107 Earth days, astronomers said.
Kepler-1647b also resides in its stars' "habitable zone" and is a gas giant. This is the reason why it doesn't have a surface. Astronomers said that any moons circling this planet could support life.
Kepler-1647b was discovered by NASA's Kepler space telescope. This telescope spots alien planets by noting the brightness dips. "It's a bit curious that this biggest planet took so long to confirm, since it is easier to find big planets than small ones," study co-author Jerome Orosz, an astronomer at San Diego State University (SDSU), said in a statement. "But it is because its orbital period is so long."
Kepler-1647b is about 3,700 light-years from Earth in the direction of the constellation Cygnus. The two parent stars of this planet are about the same size as the sun. One of the stars is a bit bigger and the other is a bit smaller. Both these stars are about 4.4 billion years old, study team members said.
Planets have been found by astronomers in a number of binary systems, but these systems had all been Saturn-size or smaller. Kepler-1647b is "the tip of the iceberg of a theoretically predicted population of large, long-period circumbinary planets," co-author William Welsh, also of SDSU, said in the same statement.