Observation data Epoch J2000 Equinox J2000 |
|
---|---|
Constellation | Cygnus |
Right ascension | 19h 16m 52.2s |
Declination | +47° 53′ 4.2″ |
Apparent magnitude (V) | 11.664 |
Characteristics | |
Spectral type | G5V |
Astrometry | |
Parallax (π) | ~5.26 mas |
Distance | 620ly (190 pc) |
Absolute magnitude (MV) | ~5.27 |
Absolute bolometric magnitude (Mbol) |
~4.98 |
Details | |
Mass | 0.970 ± 0.060 M☉ |
Radius | 0.979 ± 0.020 R☉ |
Luminosity (bolometric) | 0.8 L☉ |
Luminosity (visual, LV) | ~0.67 L☉ |
Temperature | 5518 ± 44 K |
Metallicity [Fe/H] | –0.29 ± 0.06 dex |
Rotational velocity (v sin i) | 0.6 ± 1.0 km/s |
Other designations | |
Database references | |
SIMBAD | data |
KIC | data |
Kepler-22 is a 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″. With an apparent visual magnitude of 11.7, 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). The estimated distance to Kepler-22 is 620 light-years (190 parsecs).
Kepler-22 is slightly smaller and cooler than the Sun, with a lower abundance of elements having more mass than helium. It has a spectral type of G5V, while the luminosity class remains undetermined. This star is radiating 79% of the Sun's luminosity from its outer atmosphere at an effective temperature of 5,518 K, giving it the yellow-hued glow of a G-type star. A projected rotational velocity of 0.6 km/s suggests it has a low period of rotation.
On December 5, 2011, scientists from the Kepler mission announced that a possible Earthlike world (Kepler-22b) had been discovered orbiting in the star's habitable zone by NASA's Kepler spacecraft. This was significant in that it was the first relatively Earth-sized extrasolar planet (about twice as big) confirmed to be orbiting within a star's habitable zone.