Washington: Astrophysicists using the Kepler space telescope have detected two planets the size of Saturn and a possible third the size of Earth orbiting a distant star, a report published Thursday said.
The researchers said the two giant planets -- dubbed Kepler 9b and Kepler 9c -- were transiting the star at respective speeds of 19.2 and 38.9 days.
But the speed of their transits increase or decrease by an average of four and 39 minutes respectively, because of the gravitational pull that the planets exert on each other, they reported in the online edition of the Journal Science.
Their gravitational signatures indicate the two planets are the largest bodies orbiting the stars, said Matthew Holman, an astrophysicist at Harvard University and the principal author of the findings.
The findings should enable astronomers to investigate the planets` physical condition.
They also suggest that a third planet, about the size of Earth but more than three times its mass, may also be in an orbit much closer to the star, the report said.
The new solar system discovered by the Kepler telescope is about two thousand light years from Earth. A light year is the equivalent to nearly ten trillion kilometers, or six trillion miles.
Launched in 2009, Kepler, which orbits the Sun, has been used by NASA to look for planets like the Earth orbiting other stars in the Milky Way.