Pros and amateurs team up for discovery

For the first time, amateur and professional astronomers have teamed up to discover a new planet circling a distant star. The planet was detected by looking for the effect of its gravitational field on light from a more distant star, a technique known as “microlensing.” It is only the second world to be discovered using the microlensing technique.
Gravitational microlensing offers the potential for detecting Earth-mass planets using existing or near-future technologies.

“This discovery is the tip of the iceberg for microlensing searches,” said astronomer Scott Gaudi of the Harvard-Smithsonian Center for Astrophysics. “With improving technologies and techniques, the first Earth-sized planet may be found by microlensing.”

“If an Earth-mass planet was in the same position [as the planet we found], we would have been able to detect it,” agreed Professor Andrew Gould of Ohio State University, a member of the team who made the discovery.

Microlensing searches scored their first discovery only last year. This second find confirms the power of this planet-hunting technique and heralds the beginning of routine planet detection by microlensing.

“This is the beginning of the age of microlensing. We expect many more discoveries in the coming years,” said Gaudi.

The newfound planet weighs approximately three times as much as Jupiter and probably orbits a star similar to the sun. At the time of its discovery, it was located about three times the earth-sun distance from its host star. Although its orbit is uncertain, the possibility of a “hot Jupiter” that revolves very close to its star was ruled out.