IGRINS (Immersion GRating INfrared Spectrometer) is a compact high-resolution near-infrared spectrograph that primarily disperses light with a silicon immersion grating. Individual volume phase holographic (VPH) gratings serve as cross-dispersing elements for separate spectrograph arms covering the H and K bands. IGRINS observations cover the entire wavelength range between 1.45 and 2.45μm, and do so in a single exposure with a resolving power of R~45,000. As there are no moving cryogenic parts, all observations have the same spectral format (Yuk et al. 2010, Park et al. 2014, Mace et al. 2016, Mace et al. 2018). 

Since commissioning in July 2014, IGRINS has been scheduled for more that 800 nights on the 2.7m Harlan J. Smith Telescope at McDonald Observatory, the 4.3m Discovery Channel Telescope at Lowell Observatory, and the 8.1m Gemini South telescope.

Beginning in February 2020, IGRINS will be installed on the Gemini South Telescope as a long-term visiting instrument. Observing time will be available to the astronomical community through the normal Gemini proposal process and will be scheduled in Queue, Fast Turnaround and Poor Weather modes. The 2020A Call for Proposals had a September 30, 2019 deadline for most Gemini partners. At Gemini, the slit size will be 0.34ʺ x 5ʺ. Optimal targets will be those with K-band magnitudes between 10-14, but objects between K=4 and 16 mags will be possible. A python based data reduction pipeline for IGRINS is available to the public and there is a large IGRINS user community available for collaboration.