[7] In July 2014, the International Astronomical Union launched NameExoWorlds, a process for giving proper names to certain exoplanets and their host stars.

[11] The exoplanet's discovery was announced on October 6, 1995, by Michel Mayor and Didier Queloz of the University of Geneva in the journal Nature.

[12] They used the radial velocity method with the ELODIE spectrograph on the Observatoire de Haute-Provence telescope in France and made world headlines with their announcement.

[6] The planet was discovered using a sensitive spectroscope that could detect the slight and regular velocity changes in the star's spectral lines of around 70 metres per second.

It is much closer to it than Mercury is to the Sun,[3] moves at an orbital speed of 136 km/s (300,000 mph), yet has a minimum mass about half that of Jupiter (about 150 times that of the Earth).

At the time, the presence of a huge world so close to its star was not compatible with theories of planet formation and was considered an anomaly.

However, since then, numerous other "hot Jupiters" have been discovered[3] (such as 55 Cancri and τ Boötis), and astronomers are revising their theories of planet formation to account for them by studying orbital migration.

[14] In the report of the discovery, it was initially speculated that 51 Pegasi b was the stripped core of a brown dwarf of a decomposed star and was therefore composed of heavy elements, but it is now believed to be a gas giant.