70 Virginis b

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70 Virginis b
Extrasolar planet List of extrasolar planets

70 Virginis b (Artist's impression)
Parent star
Star 70 Virginis
Constellation Virgo
Right ascension (α) 13h 28m 25.8s
Declination (δ) +13° 46′ 43.5″
Distance 59.1 ly (18.1 pc)
Spectral type G2.5Va
Orbital elements
Semimajor axis (a) 0.484 ± 0.028 AU
Eccentricity (e) 0.4007 ± 0.0035
Orbital period (P) 116.6884 ± 0.0044 d
Angular distance (θ) 26.726 mas
Longitude of
periastron
(ω) 358.71 ± 0.54°
Time of periastron (T0) 2,447,239.82 ± 0.21 JD
Semi-amplitude (K) 316.3 ± 1.7 m/s
Physical characteristics
Mass (m) >7.49 ± 0.61 MJ
Discovery information
Discovery date 17 January 1996
Discoverer(s) Geoffrey Marcy
R. Paul Butler
Detection method Doppler Spectroscopy
Discovery site Flag of the United States United States
Discovery status Confirmed
Other designations
HD 117176 b, HR 5072 b, "Goldilocks"

70 Virginis b is an extrasolar planet approximately 60 light-years away in the constellation of Virgo. Announced in 1996 by Geoffrey Marcy and R. Paul Butler, 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 (preferably in the "Goldilocks zone"), but would later be confirmed that the planet has an eccentric orbit, closer to its parent.

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[edit] Characteristics

70 Virginis b is an eccentric Jupiter type extrasolar planet which orbits its sun every 116 days with 7.5 times the mass of Jupiter, its surface Gravity must be very high nearly as much as the Sun. 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. As a result the planet's orbit was thought to be in the habitable zone and the planet was nicknamed Goldilocks (not too cold or too hot).[1] The Hipparcos satellite later showed that the star was more distant and therefore brighter resulting in the planet being too hot to be in the habitable zone.[2]

[edit] See also

[edit] References

  1. ^ Powell, Corey. "A Parade of New Planets", Scientific American, 1996-05-27. Retrieved on 2007-05-13. 
  2. ^ Perryman, M. A. C., et al. (1996). "Hipparcos distances and mass limits for the planetary candidates: 47 Ursae Majoris, 70 Virginis, 51 Pegasi" ([dead link]). Astron. Astrophys. 310: L21–L24. 

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