Unlike the names of most of the instruments, CORALIE is not an actual acronym. CORALIE was instead named after a mechanical engineer and spectrograph specialist at the Observatoire de Genève, in Switzerland. It was built as a joint project between the Observatoire de Genève in Switzerland and the Observatoire de Haute-Provence in France. It is operated by the Observatoire de Genève and its main goal is to detect extrasolar planetary companions to southern solar-type stars.

The CORALIE is an echelle spectrograph. By means of an additional cross-disperser the light is redirected in perpendicular directions,, and as a result the spectral data are displayed as a 2D pattern that can be captured by a 2D-detecting CCD camera.

CORALIE instrument was installed on April 1998 at the Swiss 1.2-metre Leonhard Euler Telescope at ESO’s La Silla Observatory. It is used in conjunction with the Leonhard Euler Telescope to conduct high precision radial velocity measurements, mainly to search for large, Jupiter-like exoplanets in the southern hemisphere. CORALIE is capable of measuring the motion of a star with a precision of 10 km/h. Didier Queloz and Michel Mayor were the leading scientists of a team that discovered about a few dozen exoplanets with CORALIE, among other scientific breakthroughs.

The CORALIE spectrograph is fed by two fibers which allow simultaneous thorium referencing. It is in an isolated and stable environment with regulated temperature to guarantee long-term stability of the measurements. The two fibers are connected to the Leonhard Euler Telescope by a front-end adapter.

The CORALIE is an improved version of the ELODIE spectrograph, which was installed at the Observatoire de Haute-Provence and that was decommissioned in August 2006 and replaced by SOPHIE.


This table lists the global capabilities of the instrument. The authoritative technical specifications as offered for astronomical observations are available from the Science Operations page.

Location: La Silla Observatory
Telescope: Swiss 1.2-metre Leonhard Euler Telescope
Focus: Nasmyth
Type: Spectrograph
Wavelength range: 390–680 nm
Spatial resolution: 100 000
Spectral resolution: R ~50000
First light: May 1998
Science goal: Exoplanetary science
Images taken with the instrument: Link
Images of the instrument: Link
Videos of the instrument: Link
Press Releases with the instrument: Link
  • Observatoire de Haute-Provence (France)
  • Observatoire de Genève (Switzerland)
  • ESO