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

3 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
CountryUnited States

Bibliographical note

Funding Information:
The authors acknowledge support from NSF Collaborative Research grant 1608834. JMS is supported by NASA through Hubble Fellowship grant HST-HF2-51398.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. The LBT is an international collaboration among institutions in the United States, Italy and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona university system; Is-tituto Nazionale di Astrofisica, Italy; LBT Beteiligungs-gesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota and University of Virginia.

Publisher Copyright:
© 2018 SPIE.


  • Exoplanet Characterization
  • High-Contrast
  • Integral Field Spectroscopy

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