UCLA

We present a catalog of J-band (1.08 to 1.35 μm) stellar spectra at low resolution (R ∼ 400). The targets consist of 105 stars ranging in spectral type from O9.5 to M7 and luminosity classes I through V. The relatively featureless spectra of hot stars, earlier than A4, can be used to remove the atmospheric features which dominate ground-based J-band spectroscopy. We measure equivalent widths for three absorption lines and nine blended features which we identify in the spectra. Using detailed comparison with higher resolution spectra, we demonstrate that low-resolution data can be used for stellar classification, since several features depend on the effective temperature and gravity. For example, the CN index (1.096-1.104 μm) decreases with temperature, but the strength of a blended feature at 1.28 μm (consisting of primarily Pβ) increases. The slope of a star's spectrum can also be used to estimate its effective temperature. The luminosity class of a star correlates with the ratio of the Mg I (1.1831 μm) line to a blend of several species at 1.16 μm. Using these indicators, a star can be classified to within several subclasses. Fifteen stars with particularly high and low metal abundances are included in the catalog, and some spectral dependence on metal abundance is also found.