Properties and nature of Be stars. 25. A new orbital solution and the nature of a peculiar emission-line binary ő Sagittarii
Abstract
The peculiar RV curve of the blue-shifted Há absorption rules out the model of a coronal flow of matter from the brighter component. The presence of bipolar jets that are perpendicular to the orbital plane and similar to those found for â Lyr seems probable.
An upper limit to the secular period decrease of 24 s per year was estimated and should be tested by future RV observations. The peculiar character of the line spectrum of the brighter component could also be understood as originating from a pseudo-photosphere of an optically thick disk rather than from a stellar spectrum.
Conclusions: .Better understanding of the nature of ő Sgr will not be possible without interferometric resolution of the binary and especially without determining its orbital inclination.