was discovered, many astronomers assumed it to be a gigantic terrestrial, because it was assumed no gas giant could exist as close to its star (0.052 AU) as 51 Pegasi b did, but it was later found to be a gas giant.

In 2005, the first planets orbiting a main-sequence star and which showed signs of being terrestrial planets were found: Gliese 876 d and OGLE-2005-BLG-390Lb. Gliese 876 d orbits the red dwarf Gliese 876,