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OHP 1.93-m telescope

The OHP 1.93-m telescope, built by Grubb-Parsons (UK), dates from late 1957. It was originally equipped with Newton, Cassegrain and Coudé foci, but only the f/15 Cassegrain focus is used now.

Telescope and building
Detailed information is available concerning the optical layout of the 1.93-m and the specifications of the telescope and optics. See also the cut-away view of the building showing the location of the observing room where the Sophie spectrograph is located in a thermally and mechanically isolated chamber.

The telescope is equipped with coordinate encoders in both axes. A pointing models allows accurate pointing and setting. A new coordinate encoding system is currently being developed. An auxiliary CCD camera has been developed in house for field acquisiton and autoguiding. An all-purpose bonnette adapter permits mounting different instruments at the Cassegrain focus.

An upgrade program of the telescope and dome is currently underway which aims at improving the pointing, slewing and auto-guiding of the system.

Focal-plane instrumentation
The instrumentation currently available includes:

  • Carelec, a long-slit (5 arc-min), low-dispersion spectrograph with all-reflecting optics, dating from early 1985, offers broad-band sensitivity (limited only by the response of the CCD) and a variety of dispersions. This instrument has been used extensively for studies of galaxy rotation curves, spectra of active galaxies and quasars and in searches for faint infrared and X-ray source counterparts.

  • Sophie, a new, cross-dispersed, high-resolution, échelle spectrograph commissioned in August 2006. This spectrograph is capable of very high precision (2-3 m/s) radial velocity measurements and features automated pipeline processing of the data at the telescope, yielding fully processed spectra and barycentric radial velocities immediately after the observation. The first extra-solar planet, 51 Peg B, was discovered in 1995 by Mayor and Queloz using this telescope and Elodie, the predecessor of this instrument.

  • Dernière mise à jour : 10 juillet 2009