Epoch J2000 Equinox J2000
|Right ascension||19h 16m 52.2s|
|Declination||+47° 53′ 4.2″|
|Apparent magnitude (V)||11.664|
|Mass||0.970 ± 0.060 M☉|
|Radius||0.979 ± 0.020 R☉|
|Temperature||5518 ± 44 K|
|Metallicity [Fe/H]||–0.29 ± 0.06 dex|
|Rotational velocity (v sin i)||0.6 ± 1.0 km/s|
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 G5, 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.
(in order from star)
|b||< 0.11 MJ||0.849 ± 0.018||289.8623 +0.016
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