HD 75289 b
Encyclopedia
HD 75289 b is an extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...

 orbiting the star HD 75289
HD 75289
HD 75289 is a 6th magnitude star in the constellation of Vela. Like our Sun, it is a yellow dwarf but slightly more massive, hotter and luminous. The spectral type of the star is G0 V...

 in Vela constellation. It has a minimum mass
Minimum mass
In astronomy, minimum mass is the lower-bound calculated mass of observed objects such as planets, stars and binary systems, nebulae, and black holes. Minimum mass is a widely cited statistic for extrasolar planets...

 half that of Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

, and it orbits in a very short orbit completing one circular revolution around the star in three and a half days. By studying the starlight scientists have concluded that the planet must have an albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...

 less than 0.12, rather low for a gas giant
Gas giant
A gas giant is a large planet that is not primarily composed of rock or other solid matter. There are four gas giants in the Solar System: Jupiter, Saturn, Uranus, and Neptune...

. Otherwise its reflected light would have been detected.

This planet was discovered on February 1, 1999 in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

, USA by Stephane Udry
Stéphane Udry
Stéphane Udry is an astronomer at the University of Geneva in Switzerland, whose current work is primarily the search for extra-solar planets. He and his team, in 2007, discovered a possibly terrestrial planet in the habitable zone of the red dwarf star Gliese 581, approximately 20 light years...

 who used the wobble method (radial velocity method).

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