ESI Home Page
Instrument Scientist: Jim Lyke
Secondary Instrument Scientist: Josh Walawender
Email Contact: ESI Support
Pre-Observing Observing Post-Observing
Follow this link for information about pre-observing activities: proposal preparation, mask design and submission, pre-run activities, etc. Follow this link for information about your observing run: instrument and telescope setups, scripts, software, procedures, etc. Follow this link for information about your post-observing activities: backups, comment forms, data reduction, etc.
Trouble Shooting Technical Pages Index
Trouble Shooting pages and links. Portal to the technical pages: for the initiated only! A listing of the instrument pages.

The Echellette Spectrograph and Imager (ESI) is a visible-wavelength, faint-object, imager and single-slit spectrograph in operation at the Cassegrain focus of the Keck II telescope since 1999. ESI was designed and built at UCO/Lick Observatory under the leadership of Principal Investigator J. S. Miller and Project Manager Dave Cowley. Notable features of ESI include:

  • Cross-dispersed spectroscopy mode along a 20 arcsec slit at a FWHM resolving power of up to R=13,000
  • Low-dispersion spectroscopy mode along an 8 arcmin slit providing resolving power of 1000<R<6000
  • Direct imaging capability across a 2×8 arcmin field
  • Wide spectral range provides complete coverage from 0.39 to 1.1µm in a single exposure
  • Open-loop flexure compensation system maintains image stability of ±0.25 px over full rotation
  • High throughput

Please make sure to check the latest news.

Principal Investigator: Joe Miller (UCO/Lick) ESI Reference (via ADS)
Sheinis et al. 2002, PASP, 114, 851.
Project Manager: Dave Cowley (UCO/Lick)


Echellete mode optical layout.


ESI on the K2 Deck.
Last modified: 02/27/2021 03:53
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