Commissioning and on-sky performance verification of iLocater
arXiv:2607.27332
The paper describes the commissioning and first on‑sky performance of iLocater, a high‑resolution near‑infrared spectrograph on the Large Binocular Telescope, demonstrating its ability to obtain precise radial‑velocity measurements and spatially resolved spectra of close binary stars.
Abstract
iLocater is a high-resolution near-infrared extreme precision radial velocity (EPRV) spectrograph that was deployed to the Large Binocular Telescope (LBT) in June 2026. iLocater operates over nm with a median resolving power of as measured in the laboratory. We present the commissioning and initial on-sky verification program using solar and night-time observations at the LBT. First light was achieved on 27 June 2026, and nearly 150 on-sky spectra have now been recorded. Observations include single stars ranging in spectral type from B5 to M6. iLocater uses the LBT AO system, and we have demonstrated its ability to obtain spatially resolved spectra of close () binary stars.
Submitted to SPIE Astronomical Telescopes + Instrumentation 2026, Paper 14149-195. 12 figures, 4 pages