Physics Colloquium: iLocator: Searching for Earth-like exoplanets among the stellar noise

Physics Colloquium
iLocator: Searching for Earth-like exoplanets among the stellar noise

Jonathan Crass
Instrument Scientist, Imaging Science Laboratory
Department of Astronomy
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 science programs. In addition, I will describe how iLocater fits into the broader EPRV landscape, future directions for the program, and broader SMF instrument development.

Bio:
Dr. Jonathan Crass is the Instrument Scientist for the Imaging Sciences Laboratory within the Department of Astronomy at The Ohio State University (OSU). His research specializes in the development of diffraction-limited instruments and new technologies for the study of exoplanets. He is co-PI of the iLocater program and is leading its completion and delivery to the Large Binocular Telescope, Arizona, USA. Dr. Crass holds an M.Phys in Physics & Astronomy from the University of Manchester, UK and a Ph.D. in Astronomy from the University of Cambridge, UK. In addition to his research, he is a strong advocate for equity and inclusion within STEM and leads several public science outreach and engagement activities. He is a member of the Committee on Diversity, Equity, and Inclusion for the Department of Astronomy at OSU.

Intended Audience:
All are Welcome!

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