Gliese 777 b

Planetbox begin
name = Gliese 777 bPlanetbox star
star = Gliese 777A
constell = Cygnus
ra = RA|20|03|37.41
dec = DEC|+29|53|48.50
dist_ly = 51.81
dist_pc = 15.89
class = G6IVPlanetbox orbit
semimajor = 3.92
eccentricity = 0.36 ± 0.03
period = 2891 ± 85
ang_dist = 246.696
long_peri = 12.4 ± 9.3
t_peri = 2,450,628.1 ± 99.8
semi-amp = 23.5 ± 0.5Planetbox character
mass = >1.502 ± 0.13
mass_earth =
radius = ~0.998
radius_earth =
density =
gravity =
gravity_earth =
temperature = ~117Planetbox discovery
discovery_date = 19 June 2002
discoverers = Mayor et al.
discovery_method = Doppler spectroscopy
discovery_site = flagicon|France Haute-Provence
discovery_status = PublishedPlanetbox catalog
names = BD+29°3872(A)b, Gliese 777(A)b, HD 190360(A)b, HIP 98767(A)b, HR 7670(A)b

Gliese 777 b, often cataloged as Gliese 777 Ab or simply HD 190360 b, is an extrasolar planet approximately 52 light-years away in the constellation of Cygnus. The planet was discovered orbiting the primary star of the Gliese 777 system in June of 2002 (by the Geneva Extrasolar Planet Search Team) using the radial velocity method. The planet is at least one half more massive than Jupiter but roughly the same size as Jupiter. Because the inclination of the planet's orbit is not known, the true mass is unknown. But it is unlikely to be much more than the given minimum mass.

The planet has one of the longest orbits currently known for an extrasolar planet. The planet's mean distance from the star is close to the distance between Jupiter and the Sun. However, unlike Jupiter it has a eccentric orbit. At periastron the distance between the planet and the star is only 2.51 AU and at apoastron the distance is as much as 5.33 AU (compared to our Solar system, distance from Sun to the inner asteroid belt and from Sun to just beyond the orbit of Jupiter). The gravitational influence of the red dwarf companion may have caused the eccentricity of the planet.

The signal produced by the planet is very weak and the eccentricity was originally supposed to be very circular which led to speculations of a very Jupiter-like planet, with a system of several large moons like Jupiter itself. Fortunately, the inner system should be stable for Earth-like planets despite a known, smaller inner Neptune-like planet which is known to orbit the star at distance of 0.12 AU every 17 Earth Days.

See also

* 47 Ursae Majoris b
* Gliese 777 c
* Jupiter

References

*cite journal | url=http://www.aanda.org/articles/aa/full/2003/42/aa4076/aa4076.html | author=Naef "et al." | title=The ELODIE survey for northern extra-solar planets II. A Jovian planet on a long-period orbit around GJ 777 A | journal = Astronomy and Astrophysics | volume=410 | year=2003 | issue=3 | pages=1051–1054 | doi=10.1051/0004-6361:20031341

External links

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*cite journal | url=http://xxx.lanl.gov/abs/astro-ph/0306586 |author=Naef et al.|title=The ELODIE survey for northern extra-solar planets II. A Jovian planet on a long-period orbit around GJ 777 A |journal = Astronomy and Astrophysics | volume=410 | year=2003 | pages=1051–1054
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