Star Image Shape Transformer for Astronomical Slit Spectroscopy

Abstract

We present a new star image shape transformer for astronomical slit spectroscopy that consists of a plano-convex lens attached to a plane-parallel rectangular glass plate on one of the small sides, with the aim of improving the performance of spectrometric systems. The system transforms the shape of the objects into a rectangular form with the purpose of filling with light the entrance slit aperture in spectroscopic systems. The plate is set sidewise with the lens as the entrance aperture and the exit aperture of the plate is the illuminated slit seen by the spectrometric system. The aim of this transformer is also to maintain the beam characteristics, the intrinsic resolution of the spectrometers and to improve the throughput of the spectrometer and detector systems.