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.