Planet Hunters Chalk Up Another

Artist's impression of an exoplanet.  Credit:  NASA

A joint Chinese/Japanese team has announced the latest extrasolar planet discovery.  

According to a press release from the Chinese Academy of Sciences:

 A joint team of National Astronomical Observatories, CAS (NAOC) and Okayama Astrophysical Observatory, Japan, recently discovered an extrasolar planet by using 2.16m astronomical telescope and 1.88m astronomic telescope respectively. The discovery was published by Research in Astronomy and Astrophysics, January 2009.

The planet is a companion to the giant star DH 173416. Scientists from Xinglong station, NAOC and Okayama Astrophysical Observatory, Japan had been observing star DH 173416 since 2004. By adopting the radial velocity method they detected the planet and further confirmed it was a new one. The planetary companion has a minimum mass of 2.7 MJ, an eccentricity of 0.21, a semimajor axis of 1.16 AU and an orbital period of 324 days. It is the first exoplanet ever discovered by the Chinese astronomers using 2.16m astronomical telescope.

The discovery is the 335th exoplanet to be discovered, and the 284th extrasolar planetary system.