TRAPPIST-1g

TRAPPIST-1g, also known as 2MASS J23062928-0502285 g and K2-112 g, is an exoplanet orbiting around the ultra-cool dwarf star TRAPPIST-1. TRAPPIST-1 is 39 light years away from Earth in the constellation Aquarius. The planet was one of four new exoplanets discovered orbiting the star using observations from the Spitzer Space Telescope.^[1] The exoplanet is within the habitable zone of its host star.^[2] It was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured.

TRAPPIST-1g

Artist's impression of TRAPPIST-1g. (February 2018)
Discovery
Discovery date	2017
Detection method	Transit
Orbital characteristics
Eccentricity	0.00208 (± 0.00058)
Inclination	89.721 (± 0.23)
Physical characteristics
Mean diameter	14,398 km
Mean radius	5,797.6 km
Temperature	−78.65 ± 2.70 °C

TRAPPIST-1g is the second most distant known planet in its system. It is larger than Earth but less dense. This means that it likely has some form of water.