Little iLocater: paving the way for iLocater

Harris, Robert J; Crass, Jonathan; Johnson, Marshall C; Bechter, Andrew J; Power, Jennifer; Calcines Rosario, Ariadna; Crepp, Justin R; Bechter, Eric B; Sands, Brian L; Kopon, Derek; Ertel, Steve; Barboza, Santiago; Bianco, Andrea

doi:10.1093/mnras/stae2720

Little iLocater: paving the way for iLocater

Harris, Robert J; Crass, Jonathan; Johnson, Marshall C; Bechter, Andrew J; Power, Jennifer; Calcines Rosario, Ariadna; Crepp, Justin R; Bechter, Eric B; Sands, Brian L; Kopon, Derek; Ertel, Steve; Barboza, Santiago; Bianco, Andrea

Authors

Dr Robert Harris [email protected]
Assistant Professor

Jonathan Crass

Marshall C Johnson

Andrew J Bechter

Jennifer Power

Dr Ariadna Calcines Rosario [email protected]
Head of Optical Design - CfAI

Justin R Crepp

Eric B Bechter

Brian L Sands

Derek Kopon

Steve Ertel

Santiago Barboza

Andrea Bianco

Abstract

Diffraction-limited radial-velocity instruments offer a pathway towards improved precision and stability, and the exploration of new parameter spaces at high spatial and spectral resolution. However, achieving the necessary performance requires careful instrument design and considerable on-sky testing. We describe the design and construction of ‘Little iLocater’ (Lili), a compact spectrograph that has been used to validate the performance of the front-end fibre-injection system of the iLocater spectrograph. We present the design, assembly, and performance using on-sky data obtained at the Large Binocular Telescope (LBT), including extraction of spectra from standard stars, testing of the atmospheric dispersion corrector to elevations of 40°, and spatially resolved spectra from close companion systems. These results show the front-end fibre-injection system is performing as expected and is indicative of iLocater’s capabilities once installed at the LBT.

Citation

Harris, R. J., Crass, J., Johnson, M. C., Bechter, A. J., Power, J., Calcines Rosario, A., Crepp, J. R., Bechter, E. B., Sands, B. L., Kopon, D., Ertel, S., Barboza, S., & Bianco, A. (2025). Little iLocater: paving the way for iLocater. Monthly Notices of the Royal Astronomical Society, 536(3), 2421-2432. https://doi.org/10.1093/mnras/stae2720

Journal Article Type	Article
Acceptance Date	Dec 3, 2024
Online Publication Date	Dec 10, 2024
Publication Date	2025-01
Deposit Date	Jan 27, 2025
Publicly Available Date	Jan 27, 2025
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	536
Issue	3
Pages	2421-2432
DOI	https://doi.org/10.1093/mnras/stae2720
Public URL	https://durham-repository.worktribe.com/output/3353622