Kepler-63 is a G-type main-sequence star about 638 light-years away. The star is much younger than the Sun, at 0.21 billion years. Kepler-63 is similar to the Sun in its concentration of heavy elements.

The star is exhibiting strong starspot activity, with relatively cold (4700±300 K) starspots concentrated in two mid-latitude bands similar to the Sun, changing their position in a cycle with a period of 1.27±0.16 years. Due to high magnetic activity associated with its young age, Kepler-63 has a very hot corona heated to 8 million degrees, and produces over ten times the solar amount of x-rays than the Sun.

Multiplicity surveys did not detect any stellar companions to Kepler-63 by 2016.

Planetary system

In 2013 a transiting hot Jupiter planet b was detected on a tight orbit. The orbit is nearly polar to the equatorial plane of the star.

The Kepler-63 planetary system
Companion (in order from star)MassSemimajor axis (AU)Orbital period (days)EccentricityInclinationRadius
b< 0.377 MJ0.080±0.0029.4341505±0.000001<0.4587.806+0.018 −0.019°0.54±0.02 RJ