Near-InfraRed Imager (NIRI)

Gemini Instrument Support Structure + instruments

0NIRI mounted on the left-side port of Gemini North telescope

Please note, NIRI is decommissioned.

The Near-Infrared Imager (NIRI), developed by the University of Hawaii’s Institute for Astronomy, is the primary near-infrared imager at the Gemini North telescope on Maunakea, capable of detecting wavelengths ranging from 1.0 to 5 micrometers. 

In its imaging mode, NIRI has three available cameras with the following focal ratios: f/32, best for the 2.5−5 micrometer range and has a 22” x 22” field of view; f/14, has a 51” x 51” field of view (in the M band); and f/6 (AO not available), best for the 1−2.5 micrometer range and has a 120” x 120” field of view. Along with its three cameras, NIRI also has a large number of broad- and narrow-band filters. Its spectroscopy capability is currently decommissioned and not available for use.

NIRI can either be used alone or with the ALTAIR adaptive optics system to correct for distortion caused by Earth’s atmosphere. ALTAIR requires the use of a natural guide star (NGS) or a laser guide star (LGS) to measure atmospheric distortions. In NGS mode, a real star provides information for the deformable mirror as well as the overall image motion for tip and tilt. It works best with guide stars up to 12th magnitude but can handle stars as faint as 15th magnitude. In LGS mode, a laser-created guide star provides information for the deformable mirror while a nearby star as faint as magnitude 17.5 (up to 18.5 in the darkest conditions) can be used for tip and tilt. 

Planetary "First Family"

First direct images of a planetary family around a normal star using NIRI

Science Highlights of NIRI

Quick Facts

  • NIRI has made several groundbreaking discoveries, including the first direct images of multiple planets orbiting a star and a planet around a Sun-like star.
  • On Gemini North, NIRI shares a port with MAROON-X, and therefore is only available during specific times.

Near-Infrared Imager (NIRI)

Site

Maunakea

Telescope

Gemini North

Type

Imager

Wavelength range

1−5 µm

Spatial resolution:

Depends on Camera


F/6: 0.1171” per pixel

F/14: 0.0499” per pixel

F/32: 0.0219” per pixel 

Number of detectors

1 ALADDIN detector array

Detector format

1024 x 1024 pixel format

Detector total size 

27,648 square micrometers 

Spectral resolution:

Spectroscopy decommissioned 

Field of view

Depends on Camera


F/6: 120” x 120”

F/14: 51” x 51”

F/32: 22” x 22”

Filters

Over 25 broad- and narrow-band filters

Date of first light

July 2001

Science Goals

General purpose near-infrared imager (supplementary spectroscopic capabilities have been decommissioned)

Images taken with the instruments

Link

Images of the instrument

Link

Videos of the Instrument

Link

Press releases with the instrument

Link