ELI5, Why do some extrasolar planets revolve much faster than planets here in the Solar Sytem?

Question

For example:

55 Cancri b: 0.7 days
Kepler-1649c: 19.5 days
Gliese 581g: 32 days

Compare it to Earth, which is 365 days and Mercury which is 88 days. What are the factors that cause these exoplanets revolve much faster?

In: 5

Answer 1

Some of it is an observation bias. We are much better at finding extrasolar planets that orbit very fast than very slow. This is because we don’t directly see the planet. We see the blocking of light from the star as the planet moves between us and the star. That is easier when the planet is big and close to the star and does it often.