On this day in 1995 the discovery of the exoplanet by Michel Mayor and Didier Queloz of the University of Geneva was announced in the journal Nature.
Though we now know the Cosmos is awash with worlds beyond our Solar System, this planet—provisionally named Bellerophon for the monster-slayer of Greek myth who captured and tamed Pegasus, namesake of its host constellation—officially designated Dimidium (Latin for half) can be described in current parlance as a hot Jupiter, a common class of planets but as this was the first one found orbiting another sun-like star (the first were discovered in 1992 though orbiting a pulsar and wholly ghostly and alien) it was given the name for its mass being half that of our largest world. The co-discoverers were awarded the Nobel prize in physics last year—nearly a quarter of a century afterwards.