NSS Wikiastronomical unit (AU): Average distance from Earth to the Sun; 150 million km, or 93 million miles.
Gas Giant: A large planet that is not composed mostly of rock or other solid matter
Hot Jupiter: Extrasolar planets whose mass is close to or exceeds that of Jupiter , but unlike in our own solar system, where Jupiter orbits at 5 AU, the planets referred to as "Hot Jupiters" orbit within approximately 0.05 AU of their parent stars
eccentricity: The deviation from a circular form or path, as in an elliptical orbit.
light-year (ly): A unit of distance. The distance light travels in one year. 1 ly = 9.46*10^15 meter = 5.9 billion miles.