HD 10180
 View of the sky around the star HD 10180 (center) Credit: ESO | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Hydrus |
| Right ascension | 01h 37m 53.57672s[1] |
| Declination | −60° 30′ 41.4954″[1] |
| Apparent magnitude (V) | 7.33[2] |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | G1V[3] |
| Astrometry | |
| Radial velocity (Rv) | +35.2[3] km/s |
| Proper motion (μ) | RA: -14.60[1] mas/yr Dec.: 6.51[1] mas/yr |
| Parallax (π) | 25.63 ± 0.38[1] mas |
| Distance | 127 ± 2 ly (39.0 ± 0.6 pc) |
| Details | |
| Mass | 1.062 ± 0.017[4] M☉ |
| Radius | 1.20 ± 0.318[4] R☉ |
| Luminosity | 1.49 ± 0.02[5] L☉ |
| Surface gravity (log g) | 4.39[6] cgs |
| Temperature | 5,911[6] K |
| Metallicity [Fe/H] | 0.08[6] dex |
| Rotation | 24 ± 3 days[5] |
| Rotational velocity (v sin i) | < 3[5] km/s |
| Age | 7.3[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 10180, also designated 2MASS J01375356-6030414,[8] is a Sun-like star in the southern constellation Hydrus that is notable for its large planetary system. Since its discovery, at least six planets, and possibly as many as nine, have been observed orbiting it, making it potentially the largest of all known planetary systems, including the Solar System.[9][5] Other stars with a large known number of planets include Kepler-90, TRAPPIST-1, Kepler-11, and 55 Cancri.
Characteristics[]
Based upon parallax measurements, it is located at a distance of about 127 light-years (39 parsecs) from Earth.[10] The apparent visual magnitude of this star is 7.33, which is too faint to be viewed with the naked eye although it can be readily observed with a small telescope.[11] At a declination of −60°, this star cannot be seen at latitudes north of the tropics.
HD 10180 is a G1V-type star, and thus generates energy at its core through the thermonuclear fusion of hydrogen. The mass of this star is estimated as 6% greater than the Sun's mass, it has a radius of 120% that of the Sun, and is radiating 149% of the Sun's luminosity. The effective temperature of the star's chromosphere is 5,911 K, giving it a yellow-hued glow like the Sun.[12] HD 10180 has a 20% higher abundance of elements other than hydrogen/helium compared to the Sun.[note 1] With an estimated age of 7.3 billion years, it is a stable star with no significant magnetic activity. The estimated period of rotation is about 24 days.[5]
A survey in 2015 ruled out the existence of any stellar companions at projected distances from 13 to 324 astronomical units.[13]
Planetary system[]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (unconfirmed) | >1.3 ± 0.8 M
|