70 Virginis b (abbreviated 70 Vir b) is an

extrasolar planet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

approximately 60 light-years away in the constellation of

Virgo Virgo may refer to: *Virgo (astrology), the sixth astrological sign of the zodiac * Virgo (constellation), a constellation *Virgo Cluster, a cluster of galaxies in the constellation Virgo *Virgo Stellar Stream, remains of a dwarf galaxy * Virgo Su ...

. Announced in 1996 by

Geoffrey Marcy Geoffrey William Marcy (born September 29, 1954) is an American astronomer. He was an early influence in the field of exoplanet detection, discovery, and characterization. Marcy was a professor of astronomy at the University of California, Berke ...

and

R. Paul Butler Robert Paul Butler (born 1960) is an astronomer and staff scientist at the Carnegie Institution for Science in Washington, D.C., who searches for extrasolar planets. he and his team have discovered over half of the planets found orbiting nea ...

, 70 Virginis was one of the first stars confirmed to have planets orbiting it. When first announced, 70 Virginis b was considered to be within its star's

habitable zone In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.J. F. Kast ...

(preferably in the "

Goldilocks zone In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.J. F. Ka ...

"), but it was later confirmed that the planet has an eccentric orbit, closer to its parent.

Characteristics

70 Virginis b is a

gas giant A gas giant is a giant planet composed mainly of hydrogen and helium. Gas giants are also called failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System. The term "gas giant" ...

that is 7.4 times the

mass Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different eleme ...

Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandth t ...

and is in an eccentric 116-day orbit about its host. Its

surface gravity The surface gravity, ''g'', of an astronomical object is the gravitational acceleration experienced at its surface at the equator, including the effects of rotation. The surface gravity may be thought of as the acceleration due to gravity experien ...

is expected to be about six to eight times that of Jupiter's. At the time of discovery in January 1996, it was believed that the star was only 29 ly away resulting in the star being less luminous based on its

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

. As a result, the planet's

orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as ...

was thought to be in the

and the planet was nicknamed

Goldilocks "Goldilocks and the Three Bears" (originally titled "The Story of the Three Bears") is a 19th-century English fairy tale of which three versions exist. The original version of the tale tells of an obscene old woman who enters the forest hom ...

(not too cold or too hot). The Hipparcos satellite later showed that the star was more distant from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

and therefore brighter resulting in the planet being too hot to be in the habitable zone. A significant update to the 70 Virginis system revised the orbit of the planet and used interferometry to show that, although the host star is similar in mass and temperature to the Sun, it is almost twice the radius of the Sun. The accuracy of these stellar parameters allowed the Habitable Zone to be calculated much more precisely, and orbital dynamics simulations show that a terrestrial planet can retain a stable orbit in the Habitable Zone despite the presence of the nearby eccentric giant planet.

References

External links

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SolStation: 70 Virginis
{{DEFAULTSORT:70 Virginis B Virgo (constellation) Giant planets Exoplanets discovered in 1996 Exoplanets detected by radial velocity

Characteristics

See also

References

External links