A new Nasmyth mirror mechanism increases the number of focal stations of the Mercator Telescope

摘要

Originally, the Mercator telescope (Roque de Los Muchachos Observatory, La Palma) only had one Cassegrainand one Nasmyth focal station available. Both foci are currently occupied and the exploitation scheme of theMercator telescope does not allow regular instrument changes. To accommodate our new three-channel imagerMAIA and to allow exible scheduling with rapid follow-up of transient phenomena, we have designed and builta new mechanism for the Nasmyth mirror that enables the use of the second Nasmyth focal station and of twocompact intermediate foci at the front and the rear side of the telescope tube. This mechanism uses high-precisiongears, bearings and optical encoders to allow for exible and very accurate positioning of the Nasmyth mirroralong the rotation and tilt axes. It is controlled by a programmable logic controller (PLC) that is the precursorof a completely new PLC and OPC-UA based telescope control system. We present the design, the constructionand the performance of this new Nasmyth mirror mechanism.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.