Kepler-84 and Its Five-Planet System

Kepler-84 is a star located 3340 light-years away. It is a single-star system, and five planets have been identified around it.

The star itself is 3.98 billion years old. Its mass is 1.06 solar masses, its radius is 1.11 solar radii, and its temperature is 6040 K. Compared with the Sun, the star's reported radius estimate is larger, and its reported temperature is hotter.

All five planets were found by the transit method, in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness.

Kepler-84 d was discovered in 2014 and is classified as Earth-like, with a radius of 1.38 Earth radii and an orbital period of 4.22 days. Among the listed planets, it has the shortest year and the smallest radius by reported estimates. Kepler-84 b, discovered in 2012, is a Super-Earth with a radius of 2.23 Earth radii and an orbital period of 8.73 days, the second-shortest year among the listed planets. Kepler-84 c, also discovered in 2012, is a Super-Earth with a radius of 2.36 Earth radii and an orbital period of 12.9 days; its radius is the second-largest among the listed planets.

The remaining planets were both discovered in 2014. Kepler-84 e is classified as Neptune-like, with a radius of 2.6 Earth radii and an orbital period of 27.4 days. Among the listed planets, it has the largest radius and the second-longest year by reported estimates. Kepler-84 f is a Super-Earth with a radius of 2.2 Earth radii and an orbital period of 44.6 days; among the listed planets, it has the longest year and the second-smallest radius by reported estimates. Each planet's reported radius estimate is larger than Earth's.