Kepler-49: A Cool Dwarf and Its Four Small Worlds

Kepler-49 is an M1 V star, a small, cool red dwarf, located 1020 light-years away. Its spectral type places it among the coolest and reddest stellar classes. The star has a mass of 0.63 solar masses, a radius of 0.6 solar radii, a temperature of 4080 K, and an age of 2.88 billion years. Its mass estimate is smaller than the Sun's, as is its radius estimate, and its temperature is cooler than the Sun's. Four planets are known to orbit this host.

Kepler-49 b is a Neptune-like planet discovered by transit in 2012. It has a mass of 9.77 Earth masses, a radius of 2.58 Earth radii, and an orbital period of 7.2 days. Its radius and mass estimates are larger than Earth's, and its mean density is 3.14 g/cm³, 0.57 times Earth's. Kepler-49 c is a Super-Earth also discovered by transit in 2012. It has a mass of 8.38 Earth masses, a radius of 2.44 Earth radii, and an orbital period of 10.9 days. Its radius and mass estimates are larger than Earth's, and its mean density is 3.16 g/cm³, 0.574 times Earth's.

Two more Super-Earths join the system. Kepler-49 d was discovered by transit in 2014 and has an orbital period of 2.58 days and a radius of 1.6 Earth radii, larger than Earth's. Kepler-49 e, also found by transit in 2014, has an orbital period of 18.6 days and a radius of 1.56 Earth radii, likewise larger than Earth's.

Among the listed planets, Kepler-49 d has the shortest year, at 2.58 days, while Kepler-49 e has the longest, at 18.6 days. Kepler-49 b has the largest radius, at 2.58 Earth radii, and Kepler-49 e has the smallest, at 1.56 Earth radii.