Didier Queloz

Didier Queloz (born February 23 1966) is a Geneva-based astronomer with a prolific record in finding extrasolar planets. He is understudy to Michel Mayor.

Didier Queloz was a Ph.D. student at the University of Geneva when he and Michel Mayor discovered the first exoplanet around a main sequence star. Queloz performed an analysis on 51 Pegasi using radial velocity measurements (doppler effect), and was astonished to find a planet with an orbital period of 4.2 days. He had been performing the analysis as an exercise to hone his skills. The planet, 51 Pegasi b, challenged the then accepted views of planetary formation, being a hot jupiter or roaster.