Gliese 436 B

Gliese 436 b ( /ˈɡliːzə/) is a Neptune-sized extrasolar planet orbiting the red dwarf star Gliese 436. It was among the smallest known transiting planets in mass and radius until the much smaller Kepler discoveries started coming in 2010.

Read more about Gliese 436 B:  Discovery, Physical Characteristics, Orbital Characteristics