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 |
Distance | 26.613 ± 0.004 ly (8.160 ± 0.001 pc) |
Details[2] | |
Mass | 0.42 ± 0.05 M☉ |
Radius | 0.42 ± 0.05 R☉ |
Luminosity | 0.028 ± 0.006 L☉ |
Surface gravity (log g) | 4.83 ± 0.04 cgs |
Temperature | 3663 ± 68 K |
Metallicity [Fe/H] | −0.30 ± 0.09 dex |
Rotational velocity (v sin i) | 1.01 ± 0.80 km/s |
Other designations | |
Database references | |
SIMBAD | data |
ARICNS | data |
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]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | >6.624±0.432[13] M |