Struve–Sahade effect

The Struve Sahade effect describes in spectroscopic binary stars, the decrease of the equivalent width of the absorption lines of moving away from the observer star and the corresponding increase in which the observer component to be moved. The effect is named after the Erstbeschreibern of the phenomenon, Otto Struve, and Jorge Sahade.

The Struve Sahade effect is observed in the spectroscopic binary stars, which consist of two massive stars with a spectral type of early spectral types O or B. When one of the star to the observer moves decreases the depth of the absorption line in the spectrum and its variability hampered by the determination of the masses and luminosities of the stars from the spectrum. All hypotheses regarding the Struve Sahade effect go from interactions between the components of the binary system of:

• The double star can be a gas stream behind in its orbit back
• Between the stars and gas is exchanged their emission lines fill the absorption lines of the star on
• A massive stellar wind between the components of the binary system leads to a heating of the hemisphere facing the other star and thus to a change in the spectrum
• The stellar winds lead to a collision zone between the stars
• Increase gas flows to the components or weaken depending on the observation angle, the rotational broadening of the spectral

Stars with the Struve - Sahade effect

• AO Cassiopeia
• Canis Majoris 29
• Spica
• Akrab