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.
