Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Hercules [1] |
Right ascension | 17h 37m 53.347s [2] |
Declination | +18° 35′ 30.16″ [2] |
Apparent magnitude (V) | 9.577 [3] |
Characteristics | |
Spectral type | M1.0V [4] |
B−V color index | 1.530±0.015 [1] |
Astrometry | |
Radial velocity (Rv) | −9.55±0.1 [5] km/s |
Proper motion (μ) |
RA: 926.638
mas/
yr
[2] Dec.: 984.455 mas/ yr [2] |
Parallax (π) | 122.5546 ± 0.0176 mas [2] |
Distance | 26.613 ± 0.004
ly (8.160 ± 0.001 pc) |
Absolute magnitude (MV) | 10.08 [1] |
Details [4] | |
Mass | 0.426±0.017 M☉ |
Radius | 0.427±0.013 R☉ |
Luminosity | 0.0295±0.0007 L☉ |
Surface gravity (log g) | 4.87±0.07 cgs |
Temperature | 3,656±51 K |
Metallicity [Fe/H] | −0.23±0.16 dex |
Rotation | 38.732±0.286 d |
Rotational velocity (v sin i) | 2.49 km/s |
Other designations | |
Database references | |
SIMBAD | data |
ARICNS | data |
Gliese 686 (GJ 686 / HIP 86287 / LHS 452) [6] is a star in the constellation of Hercules, with an apparent magnitude +9.577. [3] Although it is close to the Solar System – at 26.6 light-years – it is not the closest known star in its constellation, since Gliese 661 is 20.9 light years away. [7] The closest system to this star is the bright μ Herculis, at 4.5 light years. They are followed by GJ 1230 and Gliese 673, at 7.2 and 7.6 light years respectively. [8]
Gliese 686 is one of the many red dwarfs in the Solar System neighborhood with a spectral type of M1V, [3] [6] and has an effective temperature of about 3600 K. [3] Its brightness in the visible spectrum is equal to 0.82% of that of the Sun, [9] while its total luminosity is equivalent to 2.7% that of the Sun, [10] 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. [11] It has a metallic content lower than that of the Sun; various studies estimate its index metallicity between -0.25 and -0.44. [11] [12] It has an approximate mass between 45% and 49% of the solar mass [13] and is a star with characteristics comparable to that of Lacaille 9352.
Gliese 686 has one known super-Earth planet detected by radial velocity. [3] It is orbiting close to the host star with a separation of 0.091 AU (13.6 Gm) and an orbital period of 15.5 days. Since the inclination of its orbit is unknown, only a lower bound on its mass can be determined: it has at least 6.6 times the mass of the planet Earth.
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | ≥6.624±0.432 M🜨 | 0.091±0.001 | 15.530±0.0011 | 0.050±0.030 | — | — |
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