Gliese 86

Starbox begin
name = Gliese 86Starbox observe 2s
epoch = J2000.0
constell = Eridanus
component1 = Gliese 86 A
ra1 = RA|02|10|14
dec1 = DEC|-50|50|00
appmag_v1 = 6.17
component2 = Gliese 86 B
ra2 = RA|02|10|26
dec2 = DEC|-50|49|25
appmag_v2 = Starbox character
class = K1V / D?
r-i =
v-r =
b-v = 6.12
u-b =
variable = Starbox astrometry
radial_v =
prop_mo_ra =
prop_mo_dec =
parallax = 93.65
p_error = 0.32
parallax_footnote = [cite web|url=http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=10115|title=HIP 10138|author=van Leeuwen, F.|year=2007|work=Hipparcos, the New Reduction|accessdate=2008-08-16]
space_v_u =
space_v_v =
space_v_w =
absmag_v = Starbox detail
source =
mass = 0.79
radius = 0.855 ± 0.005
gravity =
luminosity =
luminosity_bolometric =
luminosity_visual =
temperature = 5188
metal = [Fe/H] = -0.24
rotation = 31 days
age = 2.03 × 10⁹Starbox catalog
names = Gl 86, HD 13445, HIP 10138, HR 637, SAO 232658Starbox reference
Simbad = HD+13445
ARICNS =

Gliese 86, more often abbreviated Gl 86, is a K-type dwarf star approximately 35 light-years away in the constellation of Eridanus. It has been confirmed that a white dwarf orbits the primary star. As of 2000, an extrasolar planet has been confirmed to be orbiting the star.

Stellar components

The primary companion (Gliese 86 A) is a K-type dwarf star of spectral type K1V. The characteristics in comparison to our Sun are 79% the mass, 86% the radius, and 35% the luminosity. The star has a close-orbiting massive Jovian planet.

Gliese 86 B is a white dwarf star located around 21 AU from the primary star, making the Gliese 86 system one of the tightest binaries known to host an extrasolar planet. [cite journal |url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2006ApJ...646..523R&db_key=AST&nosetcookie=1 |title=Two Suns in The Sky: Stellar Multiplicity in Exoplanet Systems|author=Raghavan, D. et al.|journal=The Astrophysical Journal|volume=646|issue=1|pages=523 – 542|year=2006|doi=10.1086/504823] It was discovered in 2001 and initially suspected to be a brown dwarf, [cite journal |url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2001A%26A...370L...1E&db_key=AST&nosetcookie=1 |title=A second substellar companion in the Gliese 86 system. A brown dwarf in an extrasolar planetary system|author=Els, S. G. et al.|journal=Astronomy and Astrophysics|volume=370|pages=L1 – L4|year=2001|doi=10.1051/0004-6361:20010298] however high contrast observations in 2005 suggested that the object is probably a white dwarf star, as its spectrum does not exhibit molecular absorption features which are typical of brown dwarfs. [cite journal |url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2005MNRAS.361L..15M&db_key=AST&nosetcookie=1 |title=Gl86B: a white dwarf orbits an exoplanet host star|author=Mugrauer, M. and Neuhäuser, R.|journal=|volume=361|issue=1|pages=L15 – L19|year=2005|doi=10.1111/j.1745-3933.2005.00055.x] Assuming the white dwarf has a mass about half that of our Sun and that the linear trend observed in radial velocity measurements is due to Gliese 86 B, a plausible orbit for this star around Gliese 86 A has a semimajor axis of 18.42 AU and an eccentricity of 0.3974. [cite journal |url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2006A%26A...459..955L&db_key=AST&nosetcookie=1 |title=New constrains on Gliese 86 B. VLT near infrared coronographic imaging survey of planetary hosts|author=Lagrange, A.-M. et al.|journal=Astronomy and Astrophysics|volume=459|issue=3|pages=955 – 963|year=2006|doi=10.1051/0004-6361:20054710]

Planetary system

The preliminary astrometric measurements made with the Hipparcos space probe suggest the planet has an orbital inclination of 164.0° and a mass 15 times Jupiter, which would make the object a brown dwarf. [cite journal | url=http://www.journals.uchicago.edu/doi/full/10.1086/318927 | author=Han "et al." | title=Preliminary astrometric masses for proposed extrasolar planetary companions | journal=The Astrophysical Journal | volume=548| issue=1 | pages=L57 – L60 | year=2001 | doi=10.1086/318927 ] However, further analysis suggests the Hipparcos measurements are not precise enough to reliably determine astrometric orbits of substellar companions, thus the orbital inclination and true mass of the candidate planet remain unknown. [cite journal|url=http://adsabs.harvard.edu/abs/2001A%26A...372..935P|title=Screening the Hipparcos-based astrometric orbits of sub-stellar objects|author=Pourbaix, D. and Arenou, F.|journal=Astronomy and Astrophysics|volume=372|pages=935 – 944|year=2001|doi=10.1051/0004-6361:20010597]

The radial velocity measurements of Gliese 86 show a linear trend once the motion due to this planet are taken out. This may be associated with the orbital motion of the white dwarf companion star.

OrbitboxPlanet
exoplanet = b
mass = >3.91
semimajor = 0.113
period = 15.76491 ± 0.00039
eccentricity = 0.0416 ± 0.0072

See also

* List of stars with confirmed extrasolar planets

References

External links

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