How Big Is the Star Sirius?

Sirius, commonly referred to as the "dog star" is said to be twice as massive as the sun, with a diameter of 1.5 million miles. Its comparatively tiny companion star, called Sirius B, is only 98 percent of the sun's mass, with a diameter of 7,500 miles.

Sirius is an intensely luminous blue-white star found in the constellation Canis Major. Astronomers consider the dazzling star to be the brightest celestial star that can be viewed at night.

The proximity of Sirius to Earth is estimated to be approximately 8.6 light-years away. This proximity is said to contribute to the hot days experienced on Earth, which inspired the popular expression "the dog days of summer."