Gliese 86 b

Gliese 86 b, sometimes referred to as Gliese 86 A b (so as to distinguish the planet from companion star "B") and or shortened to Gl 86 b, is an extrasolar planet approximately 35 light-years away in the constellation of Eridanus. The planet was discovered orbiting a K-type main-sequence star (Gliese 86 AB) by French scientists in November 1998.[2] The planet orbits very close to the star, completing an orbit in 15.78 days.

Gliese 86 b

The exoplanet Gliese 86 Ab (min mass ~4 MJ) rendered by Celestia
Discovery
Discovered by	Mayor et al.[1]
Discovery site	France
Discovery date	24 November 1998[2]
Detection method	Doppler spectroscopy
Orbital characteristics
Semi-major axis	0.113 AU (16,900,000 km)[3]
Eccentricity	0.0416 ± 0.0072[3]
Orbital period	15.76491 ± 0.00039[3] d
Time of periastron	2451903.36 ± 0.59[3]
Argument of periastron	269 ± 16[3]
Semi-amplitude	376.7 ± 2.9[3]
Star	Gliese 86
Physical characteristics
Mass	>3.91[3] MJ

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 that of Jupiter, which would make the object a brown dwarf.[4] 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.[5]

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.

Star Gliese 86 B, the second star in the binary system, it is a DQ6, with a mass 0.590 of the Sun, with an 8180K temperature.[6]