A Constellation is a group or pattern of Stars. You can observe many bright stars arranged in specific patterns if you look up the sky in the night. These patterns or groups of stars are called as Constellations. The patterns typically represent an animal, mythological persons or creatures or an inanimate object.
There are many Constellations. These Constellations move in space in fixed directions. You can see up to 12 Constellations at different times during an year.
There are 88 official Constellations. Orion – the Great Hunter, Leo – the Lion, Taurus – the Bull, Canis Major – Big Dog, Canis Minor – Little Dog are a few to mention. The stars belonging to a Constellation are not near to each other. Stars are distributed in space in three dimensions which are at different distances from earth.
Since we view these Constellations from a very very far distance, they appear to us in the same plane. The stars themselves are of different sizes, brightness and vary their distance from earth.
88 Official Constellations
Naming of the Constellations
Middle Eastern, Greek and Roman cultures are bases for most of the Constellation names. The names could have ceremonial and religious significance as well. Star groupings also helped to mark passage of time between planting and harvesting.
The 48 brightest groupings of stars are called Ancient Constellations and they can be observed by naked eye. Constellations identified by astronomers later in 1500s to 1700s are known as Modern Constellations. They can be observed only using Telescopes in the southern hemisphere. There are 38 such Modern Constellations.
Movement of Stars and Constellations
The Stars and hence the Constellations appear to move across the sky from east to west. This is because we are viewing them from earth, which spins on its axis. Our Sun also rises in the east and sets in the west.
When we observe Constellations throughout the year, they shift gradually to the west dur to the Earth’s orbit around our Sun. Viewers are looking at a different direction in space at night, during summer than they look during the winter. Due to this, we see different Constellations during the year.
Major Constellations
Orion, Ursa Major, Ursa Minor, Leo and Crux are the five major Constellations. Read more about the Major Constellations here.
Ophiucus is a little known but important Constellation which can be observed in the evening sky during summer. It is one of the largest Constellations. Read more about Ophiucus here.
Sirius is the brightest star in the sky which is also known as “Dog Star” or officially “Alpha Canis Majoris” due to its position in the Constellation “Canis Major”. Read more about Sirius here.
