Intrinsic Color Indices of Stars Obtained from 2MASS Photometry

This paper is based on JHKs magnitudes of 8 842 different spectral types stars obtained from 2MASS photometry. The mean intrinsic colors have been derived with the aid of two-color diagrams for stars of luminosity classes I-II, III and IV-V. The present results are based on samples of every Sp/L, reasonably larger than any other previously used for determining infrared colors. The smoothed infrared colors are compared with those obtained by other authors. Examples of several two-color diagrams and plots of the observed and smoothed intrinsic colors vs. spectral types of luminosity classes I-II, III and IV-V are presented. Generally the newly determined infrared intrinsic colors (V-J)0, (V-H)0 and (V-Ks)0 differ significantly from those available in literature.