The nature and causes of S-type spectra are reviewed. The S star HR 1105 is shown to be a spectroscopic binary with a period of 596 days. It is the first binary of type S to have its orbit determined, notwithstanding that it is arguably the brightest S star and that the variability of its velocity has been known since 1922, the same year as type S was recognized.
- Pub Date:
- October 1984