Speaker: Jonathon Crass (Ohio State University)

Abstract: 

Speaker: Jonathon Crass (Ohio State University)

Abstract: 

Highlighted as a strategic goal in the “Worlds and Suns in Context” science theme of the 2021 “Pathways to Discovery”Decadal Survey Report, the detailed characterization of rocky exoplanet systems requires extreme precision radial velocity (EPRV) measurements to provide mass, bulk composition, and orbital information. Such high-resolution spectroscopic capabilities help assess the potential for habitability, support studies of planet formation, and maximize the scientific return of broader exoplanet missions. With such strong scientific motivation, advancing EPRV spectrographs to the centimeter-per-second level is important need, however, reaching such a goal is complex; the performance of current instruments is no longer solely dominated by systematic effects, but also by host-star stellar variability which can have an order of magnitude larger RV signature than rocky-planets. 

 iLocater is a new type of EPRV instrument under development for the dual 8.4m diameter Large Binocular Telescope (LBT) which aims to address this challenge. The instrument uses adaptive optics (AO) to efficiently inject diffraction-limited starlight into single-mode fibers (SMFs) at near-infrared wavelengths and is optimized for precision studies of late-type stars. Operating at the diffraction limit offers a multitude of advantages for generating precise Doppler time series measurements, specifically enabling high spectral resolution (R>150,000) EPRV capabilities on a large ground-based telescope. Such resolutions are critical in disentangling stellar effects from planetary signatures. 

I will present an overview of iLocater including its design, status, expected performance and unique scienceprograms. In addition, I will describe how iLocater fits into the broader EPRV landscape, future directions for the program, and broader SMF instrument development.