Design of a derotator for the 4 m DAG telescope

Abstract

This paper Silt our work on the design of a field derotator for the adaptive optics instruments platform of DAG (Dogu Anadolu Cozier vi), a new 4 in telescope for astronomical observations near the city of krzurum, l'urkey. While the telescopefollows an astronomical object, its pupil sees a rotation of the object around the optical axis which depends n the telescope geographic coordinate and the object sky coordinate. This effect is called the field rotation. This rotation needs to be compensated during the astronomical object data acquisition. In this report we demonstrate the feasibility of placing the derotator (a. K-mirror design) in the telescope fork central hole and propose a preliminary design, considering flexures.