HD 156411 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 main sequence

Main sequence

The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...

 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 156411

HD 156411

HD 156411 is a 7th magnitude G-type main sequence star located approximately 180 light years away in the constellation Ara. This star is larger, hotter, brighter, and more massive than our Sun. Also its metal content is three-fourths as much as the Sun. In 2009, a gas giant planet was found in...

, located approximately 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....

 Ara

Ara (constellation)

Ara is a southern constellation situated between Scorpius and Triangulum Australe. Its name is Latin for "altar". Ara was one of the 48 Greek constellations described by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations defined by the International Astronomical...

. This planet has at least three-fourths the mass 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 takes eight-thirds years to orbit the star at a semimajor axis of 1.81 AU

Astronomical unit

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

. However unlike most other known exoplanets, its eccentricity

Orbital eccentricity

The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...

 is not known, but it is typical that its inclination

Inclination

Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...

 is not known. This planet was detected by HARPS on October 19, 2009, together with 29 other planets.