The brightest star in the sky, known to almost all ancient civilizations, is Sirius. Orion's belt points towards Sirius, extending downwards. There, near the horizon, especially on cold winter nights, we can see a bright blue-white star flickering due to the restless atmosphere. After all, the Greek word "Sirios" means flickering, sparkling. Sirius has a magnitude of -1.5, but compared to other stars, it is not exceptionally luminous. It owes its brightness to its relatively close distance from us - 8.7 light-years, which ranks it fifth in the list of our closest stars (excluding companions). Its luminosity is 23 times greater, its diameter is 1.8 times larger, and its mass is 2.35 times greater than our Sun. Its surface temperature of 10,000 K gives it its blue-white color.