什么是 Hot Jupiter; super-Earth; sub-Neptune？

A hot Jupiter is a giant planet on a close orbit, usually taken as a minimum mass above 0.1 Jupiter masses and a period shorter than ten days. A super-Earth is a planet larger than the Earth but smaller than the radius valley, that is up to about 1.5 to 2 Earth radii, and therefore probably rocky. A sub-Neptune is a planet above the radius valley but smaller than Neptune, about 2 to 4 Earth radii, whose radius requires an envelope of light gases or volatiles.