The GMT-Consortium Large Earth Finder (G-CLEF): an optical Echelle spectrograph for the Giant Magellan Telescope (GMT)

The GMT-Consortium Large Earth Finder (G-CLEF) is an instrument that is being designed to exceed the state-of-the-art radial velocity (RV) precision achievable with the current generation of stellar velocimeters. It is simultaneously being designed to enable a wide range of scientific programs, prominently by operating to blue wavelengths (< 3500A). G-CLEF will be the first light facility instrument on the Giant Magellan Telescope (GMT) when the GMT is commissioned in 2023. G-CLEF is a fiber-fed, vacuum-enclosed spectrograph with an asymmetric white pupil echelle design. We discuss several innovative structural, optical and control system features that differentiate G-CLEF from previous precision RV instruments.