The Bonner Spectral Atlas and Three-Dimensional Classification at Low Dispersions

Abstract

Work on the third part of the Bonner Spectral Atlas: Peculiar Stars has well progressed during the past year. Observations of the more than 200 stars – photographed with a dispersion of 240 Å mm⁻¹ at Hγ on I-N plates – is nearing completion.

The arrangement of the spectra will be as follows:

1. 1. WR-stars

2. 2. O-stars Of sequence

3. 3. Peculiar B-type stars emission-line objects

4. 4. Ap-stars with various sequences: Cr-Mn-Hg-rare earths

5. 5. Asi-stars

6. 6. Am-stars

7. 7. Late-type peculiar stars Ba II, CH

8. 8. C-stars

9. 9. Late M-type stars

10. 10. S-stars

11. 11. Composite spectra

12. 12. Spectra with large rotational broadening

The 12 groups are displayed on 40 plates, each with 6–8 objects. Stars of groups 8 to 10 will be presented with different exposures in order to facilitate the discovery of faint objects.

Sample plates will be shown and discussed.