Astronomy/Exoplanets

Exoplanets
Exoplanets, or extra-solar planets, are planets orbiting stars outside of Earth's solar system. Exoplanets is one of the two topics for the 2016 Astronomy event, the other being Star and Planet Formation.

Gas Giant
Planet composed mainly of hydrogen and helium. They may possibly have rocky or icy cores. They have masses greater than 10 Earth masses. ~25% of all discovered exoplanets are gas giants.

Hot Jupiters
Gas giants that are orbits very close to its host star. It may have either formed very close to their host star or formed farther away and migrated inward. Migration is a change in orbit due to interactions with a disk of gas or planetesimals. Hot Jupiters are found within .05-.5 AU of the host star. They are extremely hot, with temperatures as high as 2400 K. They are the most common type of exoplanet found because they are the easiest to detect (because they are huge and close to the host star.) Around 50% of discovered exoplanets are Hot Jupiters.

Terrestrial Planet
Composed primarily of silicate minerals or metals.

Super-Earth
Defined exclusively by mass with upper and lower limits. Super Earths are ‘potentially’ rocky planets with up to 10 times the mass of Earth. The term ‘Super Earth’ simply refers to the mass of the planet and not to any planetary conditions, so some of these may actually be gas dwarfs.

Mini-Neptune
aka gas dwarf or transitional planet.