Sirius A is classed as a type Am star, because the spectrum shows deep metallic absorption lines, indicating an enhancement of its surface layers in elements heavier than helium, such as iron.
Sirius is a binary star system consisting of two white stars orbiting each other with a separation of about 20 AU (roughly the distance between the Sun and Uranus) and a period of 50.1 years.
The Hipparcos parallax for Sirius is only accurate to about ±0.04 light years, giving a distance of 8.6 light years. Sirius B is generally assumed to be at the same distance.