On-sky operations with the ALES integral field spectrograph

Jordan M. Stone, Andrew J. Skemer, Philip Hinz, Zack Briesemeister, Travis Barman, Charles E. Woodward, Mike Skrutskie, Jarron Leisenring

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Scopus citations


The integral field spectrograph configuration of the LMIRCam science camera within the Large Binocular Telescope Interferometer (LBTI) facilitates 2 to 5 μm spectroscopy of directly imaged gas-giant exoplanets. The mode, dubbed ALES, comprises magnification optics, a lenslet array, and direct-vision prisms, all of which are included within filter wheels in LMIRCam. Our observing approach includes manual adjustments to filter wheel positions to optimize alignment, on/off nodding to track sky-background variations, and wavelength calibration using narrow band filters in series with ALES optics. For planets with separations outside our 1"x1" field of view, we use a three-point nod pattern to visit the primary, secondary and sky. To minimize overheads we select the longest exposure times and nod periods given observing conditions, especially sky brightness and variability. Using this strategy we collected several datasets of low-mass companions to nearby stars.

Original languageEnglish (US)
Title of host publicationGround-based and Airborne Instrumentation for Astronomy VII
EditorsLuc Simard, Luc Simard, Christopher J. Evans, Hideki Takami
ISBN (Print)9781510619579
StatePublished - 2018
EventGround-based and Airborne Instrumentation for Astronomy VII 2018 - Austin, United States
Duration: Jun 10 2018Jun 14 2018

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherGround-based and Airborne Instrumentation for Astronomy VII 2018
Country/TerritoryUnited States


  • Exoplanet Characterization
  • High-Contrast
  • Integral Field Spectroscopy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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