Instrument will be able to capture all polarisation components of stellar light across a complete optical spectrum (370 to 1000nm) in a single exposure
Optical Surfaces has been selected to supply the key spectrograph optics to the Observatoire Midi-Pyrenees (Toulouse, France) for the Narval project at the Bernard Lyot telescope (TBL).
The Narval instrument will require Optical Surfaces to produce two matching off-axis parabolic mirrors from a single f2.2 Zerodur parent of 680mm diameter.
The two off-axis collimating mirrors will be finished to achieve a uniform lambda/15rms over the whole working area to ensure the required high throughput and ultra-low dispersion.
Having previously supplied similar optics for the successful Feros and Espadons projects, Optical Surfaces was selected for its proven record in manufacturing, mounting and testing demanding high precision spectrograph optics.
The Narval instrument is an adaptation of the Espadons spectropolarimeter design that currently acts as a bright time instrument for general community use at the Canada-France-Hawaii telescope.
The new instrument will be able to capture all polarisation components of stellar light across a complete optical spectrum (370 to 1000nm) in a single exposure with a resolving power of about 70,000.
Combining a polarimeter and cross-dispersed echelle spectrograph, Narval will provide a new opportunity for studying with unprecedented accuracy stellar magnetic fields, stellar surfaces, stellar interiors, and investigating stellar atmospheres and extrasolar planets.
