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GMOS

Gemini North Gemini SouthOptical
Last Modified: 
Monday, March 24, 2025 - 12:27

The two Gemini Multi-Object Spectrographs (GMOS), one on each telescope, provide 0.36-1.03 µm long-slit and multi-slit spectroscopy and imaging over a 5.5 square arcminute field of view. Each GMOS is also equipped with an Integral Field Unit (IFU) making it possible to obtain spectra from a 35 square arcsecond area with a sampling of 0.2 arcseconds. The Nod-and-Shuffle mode, which enables superior sky subtraction, is available with both GMOS-N and GMOS-S in most spectroscopic modes.

Available For Proposals at Gemini North
For more details, see the schedules and the CfPs.
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Available For Proposals at Gemini South
For more details, see the schedules and the CfPs.
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Current Instruments

  • Altair
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  • GMOS
    • Capability
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Capability Summary

  • Total wavelength range = 360−1030 nm

Imaging (Read more)

  • 5.5’ square field of view
  • 0.0807"/pixel spatial sampling
  • broad and narrow band filters

Spectroscopy

  • Resolutions (See grating options) 
    • 1260−8800 for 0.25" slit (depending on grating)
    • 210−1460 for 1.5" slit (depending on grating)
  • Modes
    • Single Longslit (Read more)
      • Slit length of 5.5’
    • Multi-Object Spectroscopy (Read more)
      • Using 5.5’ square masks
    • Integral Field Unit (IFU), fiber fed, 0.2" sampling (Read more)
      • IFU-2, 7" x 5", 1000 spaxels
      • IFU-R, 3.5" x 5", 500 spaxels

Guiding Options

  • GMOS On-Instrument Wavefront Sensor (OIWFS)
  • Periferal Wavefront Sensor 2 (PWFS2)

Get the sensitivity
Get to the integration time calculator


The GMOS were built by a collaboration of the Astronomy Technology Centre at the ROE, the University of Durham in the UK and the Herzberg Institute of Astrophysics in Canada. GMOS-N was delivered in July 2001 with GMOS-S following in December 2002.

GMOS Mechanism

Announcements

March 14, 2025

Update on air bubbles in the GMOS-N lens interfaces

April 29, 2024

GMOS tutorial on flexure-induced wavelength shift correction using sky lines

View All GMOS News

Instrument Team

gn Instrument Scientist

Julia Scharwächter

gn Additional Support Staff
    • Kristin Chiboucas
    • Teo Močnik
    • Jennifer Andrews
    • Brian C. Lemaux
    • Eunchong Kim
    • Emanuele Farina
    • Jennifer Miller
    • Sunny Stewart

Email: GMOS_N_science@gemini.edu

gs Instrument Scientist

German Gimeno

gs Additional Support Staff
    • Veronica Firpo
    • Aleksandar Cikota

Email: GMOS_S_science@gemini.edu

International Gemini Observatory

The International Gemini Observatory  provides the astronomical communities in six participant countries with state-of-the-art astronomical facilities that allocate observing time in proportion to each country's contribution. In addition to financial support, each country also contributes significant scientific and technical resources. The national research agencies that form the Gemini partnership include: the US National Science Foundation (NSF), the Canadian National Research Council (NRC), the Chilean Agencia Nacional de Investigación y Desarrollo (ANID), the Brazilian Ministério da Ciência, Tecnologia e Inovação, the Argentinean Ministerio de Ciencia, Tecnología e Innovación, and the Korea Astronomy and Space Institute (KASI). The observatory is managed by the Association of Universities for Research in Astronomy, Inc. (AURA) under a cooperative agreement with the NSF. The NSF also serves as the executive agency for the international partnership.     


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