Kepler-22
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cygnus[1] |
| Right ascension | 19h 16m 52.1904s[2] |
| Declination | +47° 53′ 03.948″[2] |
| Apparent magnitude (V) | 11.664[3] |
| Characteristics | |
| Spectral type | G5V[4] |
| Astrometry | |
| Proper motion (μ) | RA: −39.717±0.052[2] mas/yr Dec.: −66.687±0.046[2] mas/yr |
| Parallax (π) | 5.1088 ± 0.0242[2] mas |
| Distance | 638 ± 3 ly (195.7 ± 0.9 pc) |
| Absolute magnitude (MV) | ~5.27 |
| Absolute bolometric magnitude (Mbol) | ~4.98 |
| Details | |
| Mass | 0.970 ± 0.060[3] M☉ |
| Radius | 0.979 ± 0.020[3] R☉ |
| Luminosity | 0.79 ± 0.04[3] L☉ |
| Luminosity (bolometric) | 0.8 L☉ |
| Luminosity (visual, LV) | ~0.67 L☉ |
| Temperature | 5518 ± 44[3] K |
| Metallicity [Fe/H] | –0.29 ± 0.06[3] dex |
| Rotational velocity (v sin i) | 0.6 ± 1.0[3] km/s |
| Age | 7.08+1.50 −1.53 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| KIC | data |
Kepler-22 is a sun-like star in the northern constellation of Cygnus, the swan, that is orbited by a planet found to be unequivocally within the star's habitable zone. It is located at the celestial coordinates: Right Ascension 19h 16m 52.2s, Declination +47° 53′ 4.2″.[6] With an apparent visual magnitude of 11.7,[3] this star is too faint to be seen with the naked eye. It can be viewed with a telescope having an aperture of at least 4 in (10 cm).[7] The estimated distance to Kepler-22 is 638 light-years (196 parsecs).[2]
Stellar characteristics[]
Kepler-22 is slightly smaller and cooler than the Sun,[8] with a lower abundance of elements having more mass than helium.[3] It has a spectral type of G5V, while the luminosity class remains undetermined.[4] This star is radiating 79%[3] of the Sun's luminosity from its outer atmosphere at an effective temperature of 5,518 K,[3] giving it the yellow-hued glow of a G-type star.[9] A projected rotational velocity of 0.6 km/s[3] suggests it has a long period of rotation. Survey in 2015 has failed to detect any flare activity of Kepler-22.[10]
Planetary system[]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | < 0.11 MJ | 0.849 ± 0.018 | 289.8623 +0.016 −0.02 |
— | 89.764 ±0.042° | 2.4 R
|