Near‐Infrared Classification Spectroscopy:H‐Band Spectra of Fundamental MK Standards

Abstract

We present a catalog of H-band spectra for 85 stars of approximately solar abundance observed at a resolving power of 3000 with the KPNO Mayall 4 m Fourier Transform Spectrometer. The atlas covers spectral types O7-M5 and luminosity classes I-V as defined in the MK system. We identify both atomic and molecular indices and line ratios that are temperature and luminosity sensitive, allowing spectral classification to be carried out in the H-band. The line ratios permit spectral classification in the presence of continuum excess emission, which is commonly found in pre-main-sequence or evolved stars. We demonstrate that with spectra of R = 1000 obtained at signal-to-noise ratio >50, it is possible to derive spectral types within ±2 subclasses for late-type stars. These data are available electronically through the Astronomical Data Center in addition to being served on the World Wide Web.