Struve-Sahade effectとは 意味・読み方・使い方

The Struve-Sahade effect (S-S effect) occurs with a double-lined spectroscopic binary star system. A spectroscopic binary is called double-lined when the absorption lines of both stars can be observed with a spectroscope. As each member of the star system approaches the observer in turn, the absorption lines of that star are shifted toward the blue end of the optical spectrum by the Doppler effect. Likewise, as a star moves away, its lines are shifted toward the red end of the spectrum. Each of these absorption lines has a characteristic strength that depends on the physical properties of the photosphere. The Struve-Sahade effect occurs when these lines become anomalously weaker as a star's spectrum is red-shifted.