Sirius is a binary star system. It consists of the brighter component Sirius A and its companion, the white dwarf, Sirius B. Sirius can be seen in the constellation of the Canis Major, which, seen from Central Europe, is located deep above the southern horizon. Sirius also forms the southernmost point of the winter triangle to observers on the northern hemisphere.
Facts about Sirius
Sirius, also known as the Dog Star, is about twice as massive as our Sun and is almost 200 times larger than the Earth. Sirius is located at a distance of 8.6 light years. Although this may sound like a lot, the Sirius System is one of Earth’s nearest neighbors. Its age is estimated at 240 million years, which makes it a young star system. According to calculations Vega will replace it in 233000 years as the brightest star in the sky.
Visibility of the brightest star
Sirius A is the brighter component of the binary star system: its apparent magnitude is -1.46 mag. This makes Sirius A almost twice as bright as the second brightest star Canopus. Because of its brightness, Sirius A is easy to discover even for the untrained observer. Only the Sun, Moon and the planets Venus, Jupiter, Mars and Mercury shine brighter in the night sky. Its glaring bluish-white light tends to flicker strongly and often colorfully even when the air is just slightly turbulent.
When searching, it should be noted that at moderate northern latitudes it is a star in the winter sky. This means that it is visible in the daytime sky during summer and therefore cannot be seen with the naked eye. Towards the end of August it becomes visible for the first time at dawn. In winter Sirius rises in the evening and can be admired all night.
If you are searching from the southern hemisphere Sirius can be seen in the evening where it sets after the sun. Also in the morning there are good chances that you see Sirius as it rises before the sun.Pubblicato