Cryogenic spectrograph

The SPIRou spectrograph is a near infrared fiber fed double pass cross-dispersed spectrograph, based on the designs of both the ESPaDOnS spectropolarimeter on the CFHT and the HARPS high-precision velocimeter on the ESO 3.6m telescope.

The spectrograph is designed to be able to record the whole near infrared spectrum of a star (in the wavelength range 0.98-2.35 µm and in either circular or linear polarization) on a 16-million-pixel Hawaii 4RG detector in a single exposure.

The full spectrograph is included in a large cryogenic dewar cooled down at a temperature of 77K (-200 °C) and thermally stable at a precision of a few mK.

This precision is mandatory for detecting the nanometric image motions that will betray the presence of planets orbiting around the observed stars.

Instrument / Spectro