Kepler-330: A Distant Star With Two Small Worlds

Kepler-330 is a star located 2340 light-years away, and it hosts two known planets. The star is 5.13 billion years old and has 0.79 solar masses, meaning its reported mass estimate is smaller than the Sun's. Its radius is 0.76 solar radii, also smaller than the Sun, and its temperature of 5030 K is cooler than the Sun's.

Both planets were discovered by the transit method in 2014. During a transit, a planet passes in front of its star from our viewpoint, causing a small dip in observed brightness; repeated dips help establish orbital periods. Kepler-330 b is classified as Earth-like. It has a radius of 1.35 Earth radii, which is the smallest radius among the listed planets, and an orbital period of 8.26 days, the shortest year among them.

Kepler-330 c is a Super-Earth with a radius of 1.95 Earth radii, larger than Earth's and the largest radius among the listed planets. Its orbital period is 16 days, giving it the longest year among the two. Planet size classes compare radius with Earth's: an Earth-like planet stays within 1.5 times Earth's radius, while a Super-Earth reaches 2.5 times. These classifications describe radius, not composition.