hot Jupiter

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An extrasolar gas giant planet having a mass that is equal to or greater than that of Jupiter and a high surface temperature resulting from a very close orbit with its star.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun planetology A planet whose characteristics are similar to Jupiter, but which orbits its parent star much more closely and thus has higher temperatures.