Finding charts and approximate coordinates for early-type stars classified from objective-prism plates of UK Schmidt Telescope (UKST) areas 778, 789, and 881 are presented. The source plate, for the first experiment (UKST areas 788/789), used to classify F0 or earlier type stars was an unwidened hypersensitized IIIaJ plate, and in the second experiment, a unsensitized IIIaJ plate was employed to classify A0 or earlier type stars. In the second experiment the prism spectral types are compared with photometric spectral types and HD catalogue measurements. Good correlation is observed between the prism and photometric data; however, the prism and HD data do not correlate well. The effectiveness of low dispersion prisms in detecting early-type stars is evaluated. It is determined that the useful range for low dispersion prism plates is 5-6 magnitudes and that low dispersion is as effective as higher dispersion prisms in detecting early-type stars.
South African Astronomical Observatory Circular
- Pub Date:
- Early Stars;
- Photographic Plates;
- Schmidt Telescopes;
- Early-Type Stars:Finding Charts