Orientation in the sky

Constellations also help us with the orientation in the sky. If we live in the northern hemisphere, we observe northern constellations during the year, while the southern constellations remain largely hidden to us.

The constellations around the celestial pole (the so-called circumpolar constellations, no star from the constellations does not set bellow the horizon) are visible from the particular place all year round. The visibility radius is the same as the latitude of the observation point. Of Czech latitudes the Ursa Major, Cassiopeia, Camelopardalis, Cepheus and the Draco belong to the circumpolar constellations.

We can divide the constellations according to the seasons in which they are observable in the sky; we often talk about constellations of spring, summer, autumn and winter skies.

Constellations and their position

Near the North Pole in the constellation of the Ursa Minor the Polaris shines. The most famous is the constellation of the Ursa Major, which contains the 7 brightest stars that form a pattern known as the Big Dipper, which we call asterism. The shaft of the Big Dipper is heading towards the second brightest star of the northern sky – Arcturus in the constellation of the Boötes. Extending the distance from the rear wheels 5 times it leads us to the Polaris. Cassiopeia with a shape resembling the letter M or W is a very distinctive constellation. The triangle formed by the bright stars of Regulus in the Leo, Spica in the Virgo and Arcturus in the Boötes helps us to orientate in the spring sky. These constellations are distinctive and easy to find. The noticeable summer triangle is made up of bright stars – Deneb in the Cygnus, Vega in the Lyra and Altair in the Aquila. The nucleus of the galaxy is hidden above the southern horizon in the Sagittarius. The red and bright Antares dominates the Scorpius. In the Scutum below the Aquila the thickening of the Milky Way is noticeable. The autumn sky does not offer any miraculous views in the evening. The summer constellations set early and only the Pleiades (the Seven Sisters) in the Taurus impress every observer. The distinctive Cassiopeia dominates the zenith. In winter, Orion dominates the sky. Bright stars of the winter sky form a kind of hexagonal. It consists of Betelgeuse with the Rigel in the constellation of the Orion, Aldebaran as the eye of the bull in the constellation of the Taurus, Capella marks out the Auriga, Castor and Pollux in the Gemini and Procyon in the Canis Minor. The brightest star of the night sky – Sirius in the constellation of the Canis Major finishes everything.