The Dog Star "Sirius" is the brightest star in the sky and the primary star in the constellation Canis Major. With an apparent visual magnitude of 15, it is a binary star meaning that it is actually a two star system. The bright star component of the system is a blue-white star 23 times as luminous as our sun and somewhat larger and considerably hotter than our sun. Its distance from the solar system is about 8.6 light years. The Dog Star was considered by the ancient Egyptians to be the most important star in the sky.