Artist impression of 51 Pegasi b. Image credit:ESO/M. Kornmesser/Nick Risinger
51 Pegasi b was discovered by Michel Mayor and Didier Queloz of the University of Geneva.
The first discovered exoplanet around a sunlike star (51 Pegasi) is located 50 light-years from Earth in the constellation of Pegasus.
On 6 October 1995 their findings were announced in Nature.
The exasolar planet was called 51 Pegasi b but unofficially it also goes by the names of Bellerophon or Dimidium.
The planet orbits its star in about 4 days. Which is much fast than Mercury around our own star, which takes about 88 days.
Location of 51 Pegasi in the Pegasus constellation:
Image credit: © 2003 Torsten Bronger
In February 2017, water was discovered on the planet's surface.
After that initial discovery, the number of exoplanets has grown exponentially. As of 1 October 2017, we're at 3,671 exoplanets.
The closest exoplanet we've discovered so far is Proxima Centauri b. It's located 4.2 light-years from Earth. It orbits the closest star to our solar system, Proxima Centauri.