Being currently in development, 4MOST (4-meter Multi-Object Spectroscopic Telescope) is the new instrument destined to equip the VISTA telescope (Visible and Infrared Survey Telescope for Astronomy) of the European Southern Observatory (ESO) located in Chile in the Paranal desert. Focus on the implication of Winlight and the Astrophysical Research centre of Lyon (CRAL) in this project. 

4MOST is a high-multiplex, wide-field, optical spectroscopic survey facility to be mounted on the VISTA telescope. Led by the Leibniz-Institute for Astrophysics Potsdam (AIP), the 4MOST project is carried out by a consortium of 15 research institutes based in France, Sweden, Germany, Switzerland, The Netherlands, Australia, and Great Britain.

As part of this major project, Winlight has provided equipment to the Astrophysical Research centre of Lyon (CRAL), which is responsible for the spectrographs that will equip the 4-meter wide-field telescope VISTA. Named LRS-A and -B, or Low Resolution Spectrographs, these systems will allow to probe deeper into the Universe, provide high-resolution spectral observations, and analyze the light of several million stars and galaxies.

Winlight has already supplied the CRAL with 38 optical components, including: Collimators for the High-Resolution Spectrographs (HRS) and Low-Resolution Spectrographs (LRS), cameras for LRS-A and -B spectrographs, as well as about ten freeform aspheric correctors, which are very difficult to produce. Indeed, those component are the first aspherical optics of 280/300mm of diameter realized by Winlight using innovative technologies, enabling it to grind and polish parabolic optics directly off-axis without requiring a master parabola.

Last December, during the CRAL acceptance review, the LRS-A spectrograph demonstrated very good optical performances, in compliance with specifications, thanks to the quality of the systems and components provided by Winlight. The spectrograph’s acceptance review was successfully concluded and allowed the equipment’ shipment to Postdam, in Germany. Since then, the CRAL teams have been conducting tests on the alignment of the complex optical systems that make up the LRS-B spectrograph, which is scheduled for delivery in the Fall. The integration of the LRS-A and -B spectrographs will be held next November at the AIP, their integration into the VISTA telescope being planned for 2023.

4MOST is the second collaboration between Winlight and the CRAL: indeed, Winlight has already realized over 2,500 optical components and subassemblies for the Multi-Unit Spectroscopic Explorer MUSE.