Kepler-18
Coordinates: 
19h 63m 19.06s, +46° 44′ 47.94″
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h 52m 19.0688s[1] |
| Declination | +44° 44′ 46.808″[1] |
| Apparent magnitude (V) | 14.0 |
| Characteristics | |
| Spectral type | G7 |
| Astrometry | |
| Proper motion (μ) | RA: −1.432±0.031[1] mas/yr Dec.: −20.313±0.028[1] mas/yr |
| Parallax (π) | 2.2804 ± 0.0168[1] mas |
| Distance | 1,430 ± 10 ly (439 ± 3 pc) |
| Details[2] | |
| Mass | 0.972 ± 0.042 M☉ |
| Radius | 1.108 ± 0.051 R☉ |
| Luminosity | 0.93 L☉ |
| Surface gravity (log g) | 4.32 ± 0.12 cgs |
| Temperature | 5383 ± 44 K |
| Metallicity [Fe/H] | 0.19 ± 0.06 dex |
| Rotational velocity (v sin i) | <4 km/s |
| Age | 10.0 ± 2.3 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Extrasolar Planets Encyclopaedia | data |
Kepler-18 is a star with almost the same mass as the Sun in the Cygnus constellation
Planetary system[]
The star is orbited by 3 confirmed planets, announced in 2011.[2] In 2021, it was found the orbital plane of Kepler-18d is slowly changing, likely under the gravitational influence of the additional giant planet.[4]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 6.9 ± 3.4 M
|