Didier Queloz and Michel Mayor detected a planetary companion to the solar-type star 51 Pegasi through periodic changes in its radial velocity. Their 1995 observations used the ELODIE spectrograph to measure the stellar Doppler shift.
The signal repeated in about four days, implying a close companion rather than a distant analogue of Jupiter. The inferred minimum companion mass was planetary. Because radial velocity measures only the line-of-sight component of the reflex motion, the orbital inclination remains part of the mass inference.[ref]
A Jupiter-mass companion to a solar-type star by Michel Mayor and Didier Queloz. pp. 355–359: periodic radial velocities, short-period solution and companion interpretation
Portrait of Didier Queloz
. Astrofisch66 (own work). CC BY-SA 4.0, via Wikimedia Commons. Source. Articles by others on the same topic
Didier Queloz is a Swiss astrophysicist renowned for his contributions to the field of exoplanet research. He is best known for his work in the discovery of the first exoplanet orbiting a sun-like star, which he achieved in 1995 alongside Michel Mayor. This groundbreaking discovery was significant in the field of astronomy, as it opened up new avenues for the study of planets outside our solar system and sparked interest in the search for potentially habitable worlds.