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Overview of NIRI's Capabilities

Gemini's Near InfraRed Imager and Spectrometer, NIRI, was built by the University of Hawaii's Institute for Astronomy. It provides a range of imaging and spectroscopy options in the 1-5 micron wavelength region.

NIRI's detector is a 1024x1024 ALADDIN InSb array. The instrument has three cameras: f/32, f/14, and f/6. In imaging mode they provide plate scales of 0.022, 0.050, and 0.117 arcsec pixels, respectively and fields of view of 22x22, 51x51, and 120x120 arcseconds squared, respectively. A large number of broad- and narrow band filters are available. Imaging with all cameras and all filters is possible, with the exceptions of the L' band at f/6 and the M band at f/6 and f/14, where the background saturates the array in the minimum exposure time. At f/6 a set of KRS5 grisms, slits of varying width, and blocking filters are available to provide low-moderate-resolution spectroscopic coverage over almost the entire 1.0-5.5μm region.

The Gemini facility adaptive optics (AO) system, ALTAIR, is available for use with NIRI at f/14 or f/32, either with a natural guide star or the laser guide star, for all imaging except in the M band (the advantage of AO at L' is modest and is only for point sources). Three f/32 grisms covering 1.05-2.41μm at f/32 at moderate resolution are also available for use with ALTAIR.

The Instrument Scientist for NIRI is Andrew Stephens. The NIRI instrument team can be contacted at niri_science 'at'


NIRI is currently available for queue and classical imaging observations only due to problems with focal plane mask and beam splitter mechanisms. Please see the Status and Availability pages for more information.

NIRI Science Highlights

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How to Use These Pages

The NIRI pages are organized as follows:

Also see the Near-IR Resources section, which contains generic information about observing at 1-5um as well as details about calibrations, standard stars, etc. that apply to NIRI, GNIRS, NIFS, Phoenix and FLAMINGOS2.