ILocater: A diffraction-limited Doppler spectrometer for the Large Binocular Telescope

Justin R. Crepp, Jonathan Crass, David King, Andrew Bechter, Eric Bechter, Ryan Ketterer, Robert Reynolds, Philip Hinz, Derek Kopon, David Cavalieri, Louis Fantano, Corina Koca, Eleanya Onuma, Karl Stapelfeldt, Joseph Thomes, Sheila Wall, Steven Macenka, James McGuire, Ronald Korniski, Leonard ZugbyJoshua Eisner, B. S. Gaudi, Fred Hearty, Kaitlin Kratter, Marc Kuchner, Giusi Micela, Matthew Nelson, Isabella Pagano, Andreas Quirrenbach, Christian Schwab, Michael Skrutskie, Alessandro Sozzetti, Charles Woodward, Bo Zhao

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contributionpeer-review

46 Citations (Scopus)


We are developing a stable and precise spectrograph for the Large Binocular Telescope (LBT) named "iLocater." The instrument comprises three principal components: a cross-dispersed echelle spectrograph that operates in the YJ-bands (0.97-1.30 μm), a fiber-injection acquisition camera system, and a wavelength calibration unit. iLocater will deliver high spectral resolution (R∼150,000-240,000) measurements that permit novel studies of stellar and substellar objects in the solar neighborhood including extrasolar planets. Unlike previous planet-finding instruments, which are seeing-limited, iLocater operates at the diffraction limit and uses single mode fibers to eliminate the effects of modal noise entirely. By receiving starlight from two 8.4m diameter telescopes that each use "extreme" adaptive optics (AO), iLocater shows promise to overcome the limitations that prevent existing instruments from generating sub-meter-per-second radial velocity (RV) precision. Although optimized for the characterization of low-mass planets using the Doppler technique, iLocater will also advance areas of research that involve crowded fields, line-blanketing, and weak absorption lines.

Original languageEnglish
Title of host publicationGround-Based and Airborne Instrumentation for Astronomy VI
EditorsChristopher J. Evans, Luc Simard, Hideki Takami
Place of PublicationWashington, US
Number of pages13
ISBN (Electronic)9781510601956
Publication statusPublished - 2016
EventGround-Based and Airborne Instrumentation for Astronomy VI - Edinburgh, United Kingdom
Duration: 26 Jun 201630 Jun 2016

Publication series

NameProceedings of SPIE
ISSN (Print)0277-786X


OtherGround-Based and Airborne Instrumentation for Astronomy VI
CountryUnited Kingdom


  • Adaptive optics
  • Exoplanets
  • Optical fibers
  • Radial velocity
  • Spectroscopy

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