What is a “hot Jupiter” planet?
Discovered in 1995, the “hot Jupiters” are perhaps the biggest surprise in modern planetary science. These are Jupiter-sized planets that orbit much closer to their stars than even Mercury in our solar system. There are no “hot Jupiters” in the solar system, but about 1/6 of extrasolar planetary systems known to date have them. The fraction of planetary systems that has them is probably lower than 1/6: these are the easiest planets to detect, so we detect more of them. For more information, see here .
