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Gliese 686

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.