SIMBAD references

The systematic, spectroscopic two-dimensional classification of the HD stars by N. H. is approximately three-quarters complete. Over 161,000 stars have been classified visually using 10° objective-prism plates (2 Å resolution) taken at CTIO with the Michigan Curtis Schmidt telescope. The published portion of this large, homogeneous database, taken from volumes 1-5 of the Michigan Spectral Catalogue (declination -90° to +5°), has been used to investigate the Galactic (l, b) distributions of the objects primarily via Aitoff equal-area projection plots. Particular attention has been given to the normal dwarfs and giants, the supergiants, and many of the spectroscopically peculiar classes of stars, such as the WR, Be, shell, Ap, Am, δ Del, C, S, CH, Ba, and CN stars.