Based on what we know about our own solar system, the discovery of hot jupiters came as a surprise to scientists because these planets are

Ok so i did some research and this might just help you out: Hot Jupiter's are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (P<10 days). Scientist never would of though this was possible to have the almost alike planet but in  a different form of gases. Scientists were shocked by the characteristics by these planets and were surprised how hot they got.

A thank and a brainlist would be greatly appreciated :)