title: Doppler spectroscopy as a path to the detection of Earth-like planets.
abstract: Doppler spectroscopy was the first technique used to reveal the existence of extrasolar planetary systems hosted by solar-type stars. Radial-velocity surveys led to the detection of a rich population of super-Earths and Neptune-type planets. The numerous detected systems revealed a remarkable diversity. Combining Doppler measurements with photometric observations of planets transiting their host stars further provides access to the planet bulk density, a first step towards comparative exoplanetology. The development of new high-precision spectrographs and space-based facilities will ultimately lead us to characterize rocky planets in the habitable zone of our close stellar neighbours.
authors.affiliation: Geneva Observatory, University of Geneva, 51 Chemin des Maillettes, 1290 Versoix, Switzerland.
authors.forename: Michel
authors.initials: M
authors.lastname: Mayor
authors.affiliation: Geneva Observatory, University of Geneva, 51 Chemin des Maillettes, 1290 Versoix, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Lovis
authors.affiliation: 1] Centro de Astrofisica e Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal. [2] Instituto de Astrofísica e Ciências do Espaço, Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal.
authors.forename: Nuno C
authors.initials: NC
authors.lastname: Santos