Curious, these inflated hot Jupiters

Astronomers have so far found more than five hundred "exoplanets", i. e. planets orbiting other stars. A group of these are large planets with orbits very close to their host stars, the so-called "hot Jupiters". Their mass is similar to our Jupiter but they are often much bigger, indicating that their interior is much hotter. Left to themselves, they should cool down and deflate fairly rapidly to a size similar to the Jupiter in our solar system.