# The Infrared Telescope Facility (IRTF) Spectral Library: Cool Stars

## TL;DR

This paper introduces a comprehensive infrared spectral library of 210 cool stars, useful for stellar physics, classification, and galaxy studies, with spectra calibrated and available online.

## Contribution

The creation of a high-resolution, flux-calibrated infrared spectral library of diverse cool stars with preserved continuum shapes and broad applications.

## Key findings

- Spectra cover 0.8-5 microns at R ~ 2000.
- Includes stars with well-established MK classifications.
- Library is publicly available for research use.

## Abstract

We present a 0.8 -5 micron spectral library of 210 cool stars observed at a resolving power of R = lambda / Delta lambda ~ 2000 with the medium-resolution infrared spectrograph, SpeX, at the 3.0 m NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. The stars have well established MK spectral classifications and are mostly restricted to near-solar metallicities. The sample contains the F, G, K, and M spectral types with luminosity classes between I and V, but also includes some AGB, carbon, and S stars. In contrast to some other spectral libraries, the continuum shape of the spectra are measured and preserved in the data reduction process. The spectra are absolutely flux calibrated using Two Micron All Sky Survey (2MASS) photometry. Potential uses of the library include studying the physics of cool stars, classifying and studying embedded young clusters and optically obscured regions of the Galaxy, evolutionary population synthesis to study unresolved stellar populations in optically-obscured regions of galaxies, and synthetic photometry. The library is available in digital form from the IRTF website.