A joint Geneva-Haute-Provence-Marseille project, Elodie is a fixed-configuration, cross-dispersed échelle spectrograph installed (since June 1993) at the second floor of the 1m93 telescope building in a temperature-controlled room. It is illuminated by two optical fiber bundles from the Cassegrain focus, used for star-sky or star-Thorium observations. A thinned Tektronix 1Kx1K CCD is used as a detector and a novel optical layout, due to A. Baranne, yields two interleaved sets of 67 equally-spaced orders covering a 3000Å bandpass (JPEG 56 Kbytes) (3850-6800Â) with a resolution of 45000. The integrated software features entirely automatic data reduction (bias and flat-field correction, wavelength calibration, optimal extraction) as well as on-line numerical cross-correlation with suitable masks, which yields highly accurate radial velocities (down to 15 m/s, as discussed in the "Lettre de l'OHP" No. 14 dated Spring 1995). A technical publication describing the hardware and software will appear in Astronomy&Astrophysics.
Vue du spectrographe dans la salle d'intégration à l'OHP.
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