The Kepler-42 Exoplanetary System
Kepler-42 is a star with 0.13 times the mass of the Sun, and 0.17 times its radius. It is located 126.22 light years away from the solar system and is estimated to be 4.5 billion years old, as compared to the Sun which is roughly 4.6 billion years old.
Kepler-42 is known to have 3 exoplanets in orbit around it.
Kepler-42 b was discovered by the Kepler observatory using the transit method. Its discovery was announced in 2012-03. Its semi-major axis is 0.01 astronomical units, as compared to Earth's which is 1 astronomical unit. It takes 1.21 Earth days to complete an orbit around its host star, Kepler-42.
The mass of Kepler-42 b is 0.54 times the mass of Earth. The radius of Kepler-42 b is 0.78 that of Earth. At less than 1.5 Earth masses, Kepler-42 b is a regular terrestrial planet, much like the terrestrial planets we find in our solar system, namely Mercury, Venus, Earth and Mars.