Spectrographs for the Measurement of Radial Velocities

Abstract

AbstractIn this article I discuss the design of échelle spectrographs for the measurement of radial velocities. I consider the attainment of very high precision, and whether we can do still better than the current generation of instruments, and what problems have been resolved and what problems still remain to be solved in spectrograph design. The article makes special reference to the design principles followed in the Marseille-Geneva instrument ELODIE, for which the goal has been the measurement of stellar radial velocities of high precision using an R4 échelle grating.