Topic summary
Algol A
Extracted from the Wikipedia article Algol.
System
Algol is a multiple-star system with three confirmed and two suspected stellar components. From the point of view of the Earth, Algol Aa1 and Algol Aa2 form an eclipsing binary because their orbital plane contains the line of sight to the Earth. The eclipsing binary pair is separated by only 0.062 astronomical units (au) from each other, whereas the third star in the system (Algol Ab) is at an average distance of 2.69 au from the pair, and the mutual orbital period of the trio is 681 Earth days. The total mass of the system is about 5.8 solar masses, and the mass ratios of Aa1, Aa2, and Ab are about 4.5 to 1 to 2.5.