Gliese 163
Red dwarf star in the constellation Dorado
From Wikipedia, the free encyclopedia
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[1] and an absolute magnitude of 10.91.[1] This system is located at a distance of 49.4 light-years from the Sun based on parallax measurements.[2] Judging by its space velocity components, it is most likely a thick disk star.[3]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Dorado[1] |
| Right ascension | 04h 09m 15.66834s[2] |
| Declination | −53° 22′ 25.2900″[2] |
| Apparent magnitude (V) | 11.79[1] |
| Characteristics | |
| Spectral type | M3.5V[3] |
| B−V color index | 1.480±0.008[1] |
| Astrometry | |
| Radial velocity (Rv) | 58.30±0.24[2] km/s |
| Proper motion (μ) | RA: 1046.236±0.019 mas/yr[2] Dec.: 584.166±0.023 mas/yr[2] |
| Parallax (π) | 66.0705±0.0172 mas[2] |
| Distance | 49.36 ± 0.01 ly (15.135 ± 0.004 pc) |
| Absolute magnitude (MV) | 10.91[1] |
| Details | |
| Mass | 0.405±0.010[4] M☉ |
| Radius | 0.409+0.017 −0.016[4] R☉ |
| Luminosity | 0.02163±0.00063[4] L☉ |
| Surface gravity (log g) | 4.87[5] cgs |
| Temperature | 3,460+76 −74[4] K |
| Metallicity [Fe/H] | 0.1±0.1[6] dex |
| Rotation | 61.0±0.3 d[7] |
| Rotational velocity (v sin i) | 0.85[8] km/s |
| Age | 5[9] Gyr |
| Other designations | |
| GJ 163, HIP 19394, LHS 188, LTT 1881[10] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| ARICNS | data |
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.[6] 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%[6] 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 to potentially be in the star's habitable zone, although it is hotter than Earth, with a temperature of 60 deg. C (140 deg. F). It has an eccentricity estimated to be about 0.03, giving it a fairly circular orbit. 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,[6] and in a paper submitted to arXiv in June 2019, that and another planet were possibly found, thus giving the system a total of five planets,[13] but only the first three are confirmed.[14]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| b | ≥9.9±2.3 M🜨 | 0.060+0.005 −0.006 |
8.6312+0.0023 −0.0021 |
0.02+0.12 −0.02 |
— | — |
| c | ≥7.6+2.9 −2.3 M🜨 |
0.124+0.010 −0.013 |
25.637±0.042 | 0.03+0.18 −0.03 |
— | — |
| f (unconfirmed) | ≥6.8±4.4 M🜨 | 0.326+0.027 −0.034 |
109.5+1.6 −1.4 |
0.04+0.23 −0.04 |
— | — |
| e (unconfirmed) | ≥13.6+8.2 −6.5 M🜨 |
0.700±0.066 | 349+12 −10 |
0.03+0.25 −0.03 |
— | — |
| d | ≥20.2±7.6 M🜨 | 1.021+0.088 −0.118 |
604+29 −24 |
0.02+0.22 −0.02 |
— | — |