Searching for Earth-like exoplanets among stellar noise: advancing EPRV instrument capabilities

Nov 17, 2022 - 11:00 am to 12:00 pm

Campus, PAB 102/103

Jonathan Crass (University of Notre Dame) In Person and zoom

Zoom Recording

The study and characterization of nearby terrestrial worlds continues to be a key research area within astronomy. Extremely precise radial velocity (EPRV) measurements are critical for this work providing mass, density, and orbital information that are crucial to characterize rocky worlds. However, the path to reaching the radial velocity precision required to detect Earth-analog systems (1-10cm/s) is less clear. Performance of modern Doppler instruments is no longer dominated by instrument systematics, but instead by the effects of stellar variability, an effect that imprints the signature of surface inhomogeneities and stochastic motions onto stellar spectra at the meter-per-second level. New technologies and techniques are required to address this challenge and to enable future exoplanet discoveries.

iLocater is a new type of EPRV instrument under development for the dual 8.4m diameter Large Binocular Telescope (LBT). The instrument uses adaptive optics (AO) to efficiently inject diffraction-limited starlight into single-mode fibers (SMFs) at near-infrared wavelengths. Operating at the diffraction limit offers a multitude of advantages for generating precise Doppler time series measurements: higher spectral resolution (R~150,000-240,000), the elimination of modal noise, two orders of magnitude lower OH emission, a compact instrument volume and improved thermal stability. The design of iLocater has been optimized to exploit these benefits, and deliver the spectral resolutions required for characterizing stellar variability.

I will present an overview of iLocater including its design, status, expected performance and unique science programs.