The GJ 4276 Exoplanetary System
GJ 4276 is a star with 0.41 times the mass of the Sun, and 0.41 times its radius. It is located 69.63 light years away from the solar system and is estimated to be 6.9 billion years old, as compared to the Sun which is roughly 4.6 billion years old.
GJ 4276 is known to have 1 exoplanets in orbit around it.
GJ 4276 b
GJ 4276 b was discovered by the Calar Alto Observatory observatory using the radial velocity method. Its semi-major axis is 0.08 astronomical units, as compared to Earth's which is 1 astronomical unit. It takes 13.35 Earth days to complete an orbit around its host star, GJ 4276.
Its eccentricity, the extent to which the shape of the exoplanet's orbit departs from a perfect circle (Earth's is 0.0167, which is why the shape of Earth's orbit is circular rather than oval in appearance), is 0.37, which means that when GJ 4276 b is at is at its closest point to its host star, 0.05 astronomical units separates the two, and when it is at its farthest point, this number is 0.11. In the case of Earth, these numbers are 0.9832899 and 1.0167103 respectively.
The mass of GJ 4276 b is 16.57 times the mass of Earth. At more than 10 Earth masses, GJ 4276 b is an ice giant, a planet that is made up mostly of volatiles like water, amonia and methane, and enveloped by a dense hydrogen and helium atmosphere, much like Uranus and Neptune in our solar system.