IUE Low-Dispersion Reference Atlas I, Normal Stars

The sequences have been constructed and the standard stars selected directly from the ultraviolet material, staying as far as possible within the general MK frame. The catalog is essentially composed of stars exhibiting normal behaviour in the ultraviolet.

A few peculiar objects have, however, been included as an illustration of typical abnormalities. This work clearly pointed out the dangers of extrapolating a spectral classification based on a given wavelength range to another one, and, in particular, of using the MK spectral type alone outside its definition range.