Ground-based and Airborne Instrumentation for Astronomy IV. Proceedings of the SPIE vol:8446 pages:46-54
Astronomical telescopes and instrumentation
Ground-based and Airborne Instrumentation for Astronomy IV date:July 2012
Originally, the Mercator telescope (Roque de Los Muchachos Observatory, La Palma) only had one Cassegrain and one Nasmyth focal station available. Both foci are currently occupied and the exploitation scheme of the Mercator telescope does not allow regular instrument changes. To accommodate our new three-channel imager MAIA and to allow exible scheduling with rapid follow-up of transient phenomena, we have designed and built a new mechanism for the Nasmyth mirror that enables the use of the second Nasmyth focal station and of two compact intermediate foci at the front and the rear side of the telescope tube. This mechanism uses high-precision gears, bearings and optical encoders to allow for exible and very accurate positioning of the Nasmyth mirror along the rotation and tilt axes. It is controlled by a programmable logic controller (PLC) that is the precursor of a completely new PLC and OPC-UA based telescope control system. We present the design, the construction and the performance of this new Nasmyth mirror mechanism.