Re-commissioning of the VLT/UT4 telescope after the Deformable Secondary Mirror installation

Abstract

During the 2nd semester of 2016, a new Deformable Secondary Mirror (DSM), part of the Adaptive Optics Facility Project at Paranal Observatory, was installed on the Unit Telescope 4. Starting end of November 2016, we then re-commissioned the telescope and the following three instruments : HAWK-I, MUSE and SINFONI. It is important to understand how a DSM, even if used in non-adaptive optics mode (i.e., in its rest/flat position), can impact the operations and the quality of the observations. We discuss here the results of this telescope and instrument re-commissioning, the challenges and problems we met, and compare the new performance to the ones obtained previously with the traditional Dornier Secondary Mirror.

AOF – first on-sky performance of the GALACSI GLAO mode (or how to close 10 loops in less than 5 minutes)

“…The Adaptive Optics Facility (AOF) is an upgrade of the VLT Yepun 8-meter diameter telescope that includes several components. The M2 Dornier is replaced by a new M2 Unit [1] hosting:…”