There’s an intriguing exoplanet out there — 400 light-years out there — that is so tantalizing that astronomers have been studying it since its discovery in 2009. One orbit for WASP-18 b around its star that is slightly larger than our Sun takes just 23 hours. There is nothing like it in our Solar System. A new study about this exoplanet, an ultra-hot gas giant 10 times more massive than Jupiter.