SpeX: 0.7-5.3 Micron Medium-Resolution Spectrograph and Imager
NASA InfraRed Telescope Facility(IRTF), Institute for Astronomy, University of Hawaii

IRTF Spectral Library


The IRTF Spectral Library is a collection of 0.8-5.0 μm mostly stellar spectra observed at a resolving power of R ≡ λ/Δλ ~ 2000 with the medium-resolution spectrograph, SpeX, at the NASA Infrared Telescope Facility (IRTF) on Mauna Kea. The current release covers mainly solar-metallicity late-type stars with spectral types between F and M and luminosity classes between I and V, but also includes AGB stars, carbon and S stars, and L and T dwarfs. We also include spectra of the giant planets, Jupiter, Saturn, Uranus, and Neptune. Later updates will add Wolf-Rayet, O, B, and A stars.

Features of the library include:

  • A spectral range of 0.8 to 2.5 μm (with a subset from 0.8 to 5.2 μm)

  • R~2000 from 0.8 to 2.5 μm and R~2500 from 2.5 to 5.2 μm

  • S/N ~ 100 at λ < 4 μm

  • Spectral continuum shape is preserved

  • Absolutely flux calibrated using Two Micron All Sky Survey (2MASS)  photometry.