Second generation of FEROS design

French-Canadian telescope project opts for Optical Surfaces to supply high precision optics…

The internationally renowned Observatoire Midi-Pyrénées (Toulouse, France) has selected Optical Surfaces Ltd. (Kenley, UK) to supply a series of optics to be used in the ESPaDOnS project at the Canada-France-Hawaii telescope (CFHT).

Funded by the European Space Agency (ESA) and the CFHT Corporation, Optical Surfaces components will form the core elements of a new bright time instrument for general community use at the CFHT. 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, the Echelle SpectroPolarimetric Device for the Observation of Stars (ESPaDOnS) will provide a unique opportunity for studying with unprecedented accuracy stellar magnetic fields, stellar surfaces, stellar interiors, and investigating stellar atmospheres and extrasolar planets.

Having supplied similar optics in 1999 for the successful FEROS project, (see New Star Found) we have a proven record in manufacturing, mounting and testing precision optics for astrophysics projects.

For The ESPaDOnS instrument we produced two matching off-axis parabolic mirrors from a single f 2.2 Zerodur parent of 680-mm diameter. A uniform lambda/15 was achieved over the whole working area to ensure the required high throughput and ultra-low dispersion on all components.

Optical layout for Espadons spectrograph
Optical layout for Espadons spectrograph