SIRIUS – brightest fixed star

Sirius is the brightest fixed star and the most prominent in the constellation "Greater (or Big) Dog“. The luminosity of Sirius exceeds that of the sun by 20 times, whereby its mass is only double the sun's. Sirius is believed to be the brightest star in the sky. It is about 85 trillion kilometers from earth (approximately 8.7 light years).

Sirius played an important role in ancient Egyptian agriculture, its appearance occurred just before the flooding of the Nile.

The "siriometer" is a rarely used unit of length in astronomy. A siriometer is the equivalent of five parsec.

The surface of Sirius B – a “white dwarf” and constant companion of Sirius A – is of enormous density. It is 300times harder than a diamond. While it turns 23 per minute on its own axis, it develops enormous magnetic fields. Both stars constantly rotate around each other and exchange particles.
In the iconography of the sky, Orion the gigantic hunter, is always pictured accompanied by his dog (Dog Star, Sirius), tracking the rabbit (Lepus).

Sirius is part of the winter constellation “Greater (or Big) Dog”, which is a small constellation on the southern horizon, that, from central Europe is easily recognized through Sirius.