Ultraviolet photometric observations of Ap and Am stars.
Abstract
ANS five color ultraviolet photometric observations of 79 hot and cool Ap stars and 26 Am stars are presented. The positions of Ap and Am stars in ultraviolet color-color diagrams differ from those of normal main-sequence stars of the same spectral type. The deviation is largest for the cooler Ap stars. The ultraviolet flux deficiency known to exist for the hot (early type) Ap stars appears to decrease towards later spectral types and is absent for the Am stars. The light variable HR 5857 shows ultraviolet light variations of which the amplitude gradually decreases towards longer wavelengths.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1978
- Bibcode:
- 1978A&A....66..187V
- Keywords:
-
- A Stars;
- Metallic Stars;
- Stellar Spectrophotometry;
- Ultraviolet Photometry;
- Absorption Spectra;
- Astronomical Netherlands Satellite;
- Cassegrain Optics;
- Color-Color Diagram;
- Magnetic Fields;
- Spectral Resolution;
- Wavelengths;
- Astronomy;
- Metallic-Line Stars:UV Photometry;
- Peculiar A Stars:UV Photometry