Near‐Infrared Classification Spectroscopy:<i>H</i>‐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 O7M5 and luminosity classes IV 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 premain-sequence or evolved stars. We demonstrate that with spectra of R = 1000 obtained at signal-to-noise ratio &gt;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.