83 Leonis

Starbox begin
name = 83 LeonisStarbox observe 2s
epoch = J2000.0
equinox = J2000.0
constell = Leo
component1 = 83 Leonis A
ra1 = RA|11|26|45.32
dec1 = DEC|+3|0|47.18
appmag_v1 = 6.49
component2 = 83 Leonis B
ra2 = RA|11|26|46.2771
dec2 = DEC|+03|00|22.781
appmag_v2 = 7.57Starbox character
class = K0IV / K2V
r-i =
v-r =
b-v =
u-b =
variable = "None"Starbox astrometry
radial_v =
prop_mo_ra =
prop_mo_dec =
parallax =
p_error =
parallax_footnote =
dist_ly = 57.61
dist_pc = 17.67
space_v_u =
space_v_v =
space_v_w =
absmag_v = Starbox detail
source =
mass = ? / 0.78
radius = 1.9 / 0.81
gravity =
luminosity = 66 /
temperature = ? / 4875
metal = 1.2 / 0.36
rotation =
age = ? / 4.49 billionStarbox catalog
names = Wolf 393, GJ 429, HD 99491/2, BD+03°2502/3, HIP 55846, HR 4414Starbox reference
Simbad = HD+99491
ARICNS = Starbox reference
Simbad = HD+99492
ARICNS =

83 Leonis, abbreviated 83 Leo, is a binary star system approximately 58 light-years away in the constellation of Leo (the Lion). The primary star of the system is a cool orange subgiant star, while the secondary star is an orange dwarf star. The two stars are separated by at least 515 astronomical units away from each other. Both stars are presumed to be cooler than the Sun.

As of 2005, an extrasolar planet [cite journal | url=http://www.journals.uchicago.edu/doi/full/10.1086/426384 | author=Marcy "et al." | title=Five New Extrasolar Planets | journal=The Astrophysical Journal | volume=619 | issue=1 | year=2005 | pages=570 – 584 | doi=10.1086/426384 ] has been confirmed to be orbiting the secondary star within the system. Because of the optical component of the two stars (which appears close to the stars because of our line-of-sight), this planet was able to be discovered.

Stellar system

The primary component, 83 Leonis A, is a 6th magnitude star. It is not visible to the unaided eye, but easily visible with small binoculars. The star is classified as a subgiant, meaning that it has ceased fusing hydrogen in its core and started to evolve towards red gianthood.

The secondary component, 83 Leonis B, is an 8th magnitude orange dwarf, somewhat less massive (0.88 M_Sun), smaller and cooler than our Sun. cite web | title=The Planet Around HD 99492 | work=California & Carnegie Planet Search | url=http://exoplanets.org/esp/hd99492/hd99492.shtml | accessdate=2006-05-09] It is visible only with binoculars or better equipment. Components A and B share common proper motion, which confirms them as a physical pair. The projected separation between the stars is 515 AU, but the true separation may be much higher. cite journal |url=http://www.journals.uchicago.edu/doi/abs/10.1086/504823| author=Raghavan "et al." | title=Two Suns in The Sky: Stellar Multiplicity in Exoplanet Systems | journal=The Astrophysical Journal | volume=646 | issue=1 | pages=523 – 542 | year=2006 | doi=10.1086/504823 | format=abstract ( [http://xxx.lanl.gov/abs/astro-ph?papernum=0603836 web Preprint] )]

There is yet another, magnitude 14.4 component listed in the Washington Double Star Catalog. However, this star is moving into a different direction and is therefore not a true member of the 83 Leonis system.

Planetary system

Planet 83 Leonis Bb was discovered in Jan 2005 by the California and Carnegie Planet Search team, who use the radial velocity method to detect planets. It is one of the smallest planets detected so far, having mass less than half that of Saturn. It orbits in a circular but a very close orbit around the star, completing one orbit in about 17 days.

PlanetboxOrbit
exoplanet = Bb
mass = >0.109±0.013
period = 17.0431±0.047
semimajor = 0.1232±0.0071
eccentricity = 0.254±0.092

See also

* 16 Cygni

References

External links

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