HD 13931 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...

 which orbits the G-type star

Star

A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

 HD 13931

HD 13931

HD 13931 is an 8th magnitude G-type star located approximately 144 light years away in the constellation Andromeda. This star is larger, hotter, brighter, and more massive than our Sun. Also its metal content is about 8% greater than the Sun...

, located approximately 144 light years away in the constellation

Constellation

In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

 Andromeda

Andromeda (constellation)

Andromeda is a constellation in the northern sky. It is named after Andromeda, the princess in the Greek legend of Perseus who was chained to a rock to be eaten by the sea monster Cetus...

. This planet takes 11.55 years to orbit the star at the average distance of 5.15 AU

Astronomical unit

An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....

 or 770 Gm

Gigametre

A gigametre is a unit of length in the metric system, equal to one billion meters, the SI base unit of length, hence to 1,000,000 km or approximately 621,370 miles....

. The planet’s eccentricity (0.02) is about the same as Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

. The orbital distance for this planet ranges from 5.05 to 5.25 AU. This planet was discovered by using radial velocity method from spectrograph

Spectrograph

A spectrograph is an instrument that separates an incoming wave into a frequency spectrum. There are several kinds of machines referred to as spectrographs, depending on the precise nature of the waves...

 taken at Keck Observatory on November 13, 2009.

See also

Other planets that were discovered or confirmed on November 13, 2009:

• HD 34445 b
  HD 34445 b
  HD 34445 b is an extrasolar planet which orbits the G-type star HD 34445, located approximately 152 light years away in the constellation Orion. This planet was discovered in 2004 and finally confirmed in 2009. This planet has a minimum mass two-thirds that of Jupiter and orbits about 2 AU from the...
  
  
• HD 126614 Ab
  HD 126614 Ab
  HD 126614 Ab, or simply HD 126614 b, is an extrasolar planet which orbits the primary K-type star HD 126614 A, located approximately 236 light years away in the constellation Taurus. It was discovered on November 13, 2009. However, this planet has a highly eccentric orbit around its parent star...
  
  
• HD 24496 Ab
  HD 24496 Ab
  HD 24496 Ab, or simply HD 24496 b, is an extrasolar planet which orbits the G-type star HD 24496 A, located approximately 160 light years away in the constellation Taurus. This is a wide-orbiting saturnian planet discovered on November 13, 2009...
  
  
• Gliese 179 b
  Gliese 179 b
  Gliese 179 b is an extrasolar planet which orbits the M-type main sequence star Gliese 179, located approximately 40 light years away in the constellation Orion. This planet has a minimum mass a little bit less than Jupiter and it orbits at 2.41 AU or 361 Gm from the star with an eccentricity...
  
  
• QS Virginis b