Kepler-29: A Distant Star with Two Transiting Worlds

Kepler-29 is a star located 2720 light-years away. It has a reported mass of 0.93 solar masses, a radius of 0.824 solar radii, and a temperature of 5360 K. Each of these reported estimates is smaller or cooler than the corresponding value for the Sun. Two planets are known to orbit this host.

Both planets were discovered by transit, the method in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness, with repeated dips helping to establish orbital periods. Both were discovered in 2011.

Kepler-29 b is a Neptune-like planet with a radius of 2.55 Earth radii and a mass of 5 Earth masses, completing an orbit in 10.3 days. Its mean density is 1.66 g/cm³, 0.302 times Earth's. Among the listed planets, it has the shortest year by reported estimates and the largest radius by reported estimates, as well as the largest reported mass.

Kepler-29 c is a Super-Earth with a radius of 2.34 Earth radii and a mass of 4.5 Earth masses, taking 13.3 days to complete one orbit. Its mean density is 1.94 g/cm³, 0.351 times Earth's. Among the listed planets, it has the longest year by reported estimates, the smallest radius by reported estimates, and the smallest reported mass.

Both planets have reported radii and masses larger than Earth's. In size classification, a Super-Earth reaches 2.5 times Earth's radius, while a Neptune-like planet reaches 4 times Earth's radius; these classes compare radius with Earth's rather than indicating composition.