Gliese 686

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Gliese 686
Observation data
Epoch J2000      Equinox J2000
Constellation Hercules
Right ascension 17h 37m 53.34674s[1]
Declination +18° 35′ 30.1607″[1]
Apparent magnitude (V) 9.577[2]
Characteristics
Spectral type M1[2]
Astrometry
Radial velocity (Rv)−9.55 ± 0.1[3] km/s
Proper motion (μ) RA: 926.741[1] mas/yr
Dec.: 984.697[1] mas/yr
Parallax (π)122.5546 ± 0.0176[4] mas
Distance26.613 ± 0.004 ly
(8.160 ± 0.001 pc)
Details[2]
Mass0.42 ± 0.05 M
Radius0.42 ± 0.05 R
Luminosity0.028 ± 0.006 L
Surface gravity (log g)4.83 ± 0.04 cgs
Temperature3663 ± 68 K
Metallicity [Fe/H]−0.30 ± 0.09 dex
Rotational velocity (v sin i)1.01 ± 0.80 km/s
Other designations
BD+18 3421, HIP 86287, G 170-55, LHS 452, 2MASS J17375330+1835295[5]
Database references
SIMBADdata
ARICNSdata

Gliese 686 (GJ 686 / HIP 86287 / LHS 452)[5] is a star in the constellation of Hercules, with an apparent magnitude +9.577.[2] Although it is close to the Solar System - at 26.5 light years - it is not the closest known star in its constellation, since Gliese 661 is 20.9 light years away.[6] The closest system to this star is the bright μ Herculis, at 4.5 light years. They are followed by and Gliese 673, at 7.2 and 7.6 light years respectively.[7]

Gliese 686 is one of the many red dwarfs in the Solar System neighborhood with a spectral type of M1V,[2][5] and has an effective temperature of about 3600 K.[2] Its brightness in the visible spectrum is equal to 0.82% of that of the Sun,[8] while its total luminosity is equivalent to 2.7% that of the Sun,[9] since a significant amount of the radiation emitted by these stars is infrared invisible light. Considering only this last parameter, Gliese 686 is considerably brighter than other known red dwarfs; thus, it is 6.5 times more luminous than Ross 154 and 15 times more than Proxima Centauri, the closest star to the Solar System.

Gliese 686 has a radius approximately equal to half the solar radius. Its projected rotation speed is 2.5 km / s, its rotation period being equal to or less than 10.3 days.[10] It has a metallic content lower than that of the Sun; various studies estimate its index metallicity between -0.25 and -0.44.[10][11] It has an approximate mass between 45% and 49% of the solar mass [12] and is a star with characteristics comparable to that of Lacaille 9352.

Planetary system[]

Gliese 686 has one known super-Earth planet detected by radial velocity.[2]

The Gliese 686 planetary system
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination Radius
b >6.624±0.432[13] M
WIKI