Kepler-27 is a star in the northern constellation of Cygnus, the swan. It is located at the celestial coordinates: Right Ascension 19h 28m 56.81962s, Declination +41° 05′ 09.1405″. With an apparent visual magnitude of 15.855, this star is too faint to be seen with the naked eye. In 2024, Kepler-27 was discovered to be a binary star with a red dwarf companion 1.975 arcseconds away.

Planetary system

The planetary system of Kepler-27 comprising two small gas giants on eccentric orbits was discovered in late 2011. The planets Kepler-27b and Kepler-27c have equilibrium temperatures of 610 K and 481 K, respectively. In 2021, a third, sub-Neptune-sized planet was confirmed, orbiting closer in than the other two planets.

The Kepler-27 planetary system
Companion (in order from star)MassSemimajor axis (AU)Orbital period (days)EccentricityInclinationRadius
d0.0706.546290.2414 RJ
b0.1320±0.018 MJ0.11815.33480.522±0.024 RJ
c0.0670±0.011 MJ0.19131.33090.640±0.029 RJ

Notes