Gliese 163

Gliese 163 is a faint red dwarf star with multiple exoplanetary companions in the southern constellation of Dorado. Other stellar catalog names for it include HIP 19394 and LHS 188.^[10] It is too faint to be visible to the naked eye, having an apparent visual magnitude of 11.79^[2] and an absolute magnitude of 10.91.^[2] This system is located at a distance of 49.4 light-years from the Sun based on parallax measurements.^[1] Judging by its space velocity components, it is most likely a thick disk star.^[3]

This is a small M-type main-sequence star with a stellar classification of M3.5V.^[3] It has a relatively low activity level for a red dwarf of its mass, suggesting it is an old star with an age of at least two billion years.^[5] This star has 41% of the mass and radius of the Sun.^[4] It is spinning slowly with a projected rotational velocity of 0.85 km/s^[8] and has a rotation period of 61 days.^[7] The star is radiating just 2%^[5] of the luminosity of the Sun from its photosphere at an effective temperature of 3,460 K.^[4]

Planetary system[]

In September 2012, astronomers using the HARPS instrument announced the discovery of two planets orbiting Gliese 163.^[11][12] The first planet, Gliese 163 b, is a super-Earth or mini-Neptune with an orbital period of 9 days, therefore far too hot to be considered habitable. However, Gliese 163 c, with an orbital period of 26 days and a minimum mass of 6.9 Earth masses, was considered potentially in the habitable zone, although hotter than Earth, with a temperature of 60 deg. C (140 deg. F) It has an ecc. of 0.03 or 3 per.. Evidence was also found for a third planet orbiting further out than c and b.^[11][12]

In June 2013, it was concluded that at least 3 planets orbit around the star with a fourth planet being a possibility,^[5] and in a paper submitted to arXiv in June 2019, that and another planet were found, thus giving the system a total of five planets.^[13]