天狼星, also known as Sirius, is the brightest star in the night sky. It is located in the constellation Canis Major and is approximately 8.6 light-years away from Earth. Sirius is actually a binary star system, consisting of two stars: Sirius A, a main-sequence star, and Sirius B, a white dwarf. Sirius has been significant in various cultures throughout history. In ancient Egypt, it was associated with the goddess Isis and marked the start of the annual flooding of the Nile River. Its brightness and prominence have made it a key reference point for navigation and timekeeping in many civilizations.