Kepler-56 is a red giant in the constellation Cygnus. It is located roughly away from the solar system and has slightly more mass than the Sun.
Kepler-56 is a red giant star. This means it is no longer fusing hydrogen in its core and is off the main sequence. Its mass is around 1.3 M<sub>âÂÂ</sub>. Its radius is about 4.2 R<sub>âÂÂ</sub>, putting the star's density at about 0.025 g/cm<sup>3</sup>. For reference, the Sun's density is about 1.408 g/cm<sup>3</sup>. . Its luminosity is about 9.6 L<sub>âÂÂ</sub>, and its effective temperature is .
Kepler-56 is about 3.9 billion years old, placing it as about 600 million years younger than the Sun. Its apparent magnitude is , making it too dim to be visible to the naked eye.
In 2012, scientists discovered a two-planet planetary system around Kepler-56 via the transit method. Asteroseismological studies revealed that the orbits of Kepler-56b and Kepler-56c are coplanar but about 45ð misaligned to the host star's equator. In addition, follow-up radial velocity measurements showed evidence of a gravitational perturbator. It was confirmed in 2016 that the perturbations are caused by a third, non-transiting planet: Kepler-56d.
The planetary system is very compact but is dynamically stable.
Kepler-56 is expanding. As a result, it will devour Kepler-56b and Kepler-56c in 130 and 155 million years, respectively. 56d will be far enough to survive its parent star's red giant phase.