Known as the “Demon Star,” Algol (Beta Persei) is one of the most fascinating stars visible in the night sky. Located about 90 light-years from Earth in the constellation Perseus, Algol appears to mysteriously brighten and dim over time, a phenomenon that puzzled skywatchers for centuries.

Today, astronomers know that Algol is actually part of an eclipsing binary star system. As one star passes in front of another, it blocks some of its companion’s light, causing the system’s brightness to decrease. This cycle repeats with remarkable precision every 2.87 days, making Algol one of the first variable stars to be studied in detail.

Algol has played a crucial role in advancing our understanding of binary stars, stellar motion, and the life cycles of stars. Its predictable brightness changes continue to make it a favorite target for both amateur stargazers and professional astronomers. From ancient myths to modern science, the Demon Star remains one of the most intriguing objects in the cosmos.