Kepler-109: A Distant Star With Two Known Planets

Kepler-109 is a star located 1550 light-years away, and two planets have been identified in orbit around it. The host star is estimated to be 5.73 billion years old, with a mass of 1.04 solar masses, a radius of 1.32 solar radii, and a temperature of 5950 K. Its reported radius estimate is larger than the Sun's, and its reported temperature is hotter than the Sun's.

Kepler-109 b is classified as a Super-Earth, a size class that compares radius with Earth's and reaches 2.5 times Earth's radius. It was discovered by the transit method in 2014, when the planet passed in front of its star from our viewpoint and caused a small dip in observed brightness. Its radius is 2.49 Earth radii, its mass is a reported upper limit of 4.9 Earth masses, and its orbital period is 6.48 days. Among the listed planets, Kepler-109 b has the shortest year by reported estimates and the smallest radius by reported estimates.

Kepler-109 c is classified as Neptune-like, a size class that reaches 4 times Earth's radius. It was also discovered by transit in 2014. Its radius is 2.65 Earth radii, its mass is a reported upper limit of 8.2 Earth masses, and its orbital period is 21.2 days. Among the listed planets, Kepler-109 c has the longest year by reported estimates and the largest radius by reported estimates.