Researchers with the Microlensing Planet Search project have found evidence of the first known circumbinary planet, an object of about three times the size of Jupiter orbiting a pair of stars nearly 28,000 light-years from Earth. The findings of the team, led by David Bennett and Sun Hong Rhie of the University of Notre Dame in Indiana, suggest that extrasolar planets are more common than previously believed.

The researchers interpreted the data from a microlensing event observed in June 1997 by the Massive Compact Halo Objects program. When they discovered that two-object models could not account for the fluctuating brightness, they successfully employed a simulation for a three-body system.

Illustration courtesy of Orit Bergman of Zapa Digital Arts in Tel Aviv, Israel, and Dan Maoz of Tel Aviv University.