Andromeda
Andromeda is the constellation of the Northern hemisphere of the sky. This constellation includes three stars that correspond to the second star magnitude. It is also the spiral galaxy that could be seen with the necked eye. It is known to humanity since 10th century.
In fact the Andromeda Nebula is the most important object of the constellation. It has its satellites that are dwarfs galaxies. It can be seen even at night without moon shinning.
Though the Persian astronomer saw this galaxy calling it the little cloud, the European scientists discovered it only in the beginning of 18th century. This is the nearest spiral galaxy to us that is situated at the distance of 2.2 million light years. Although it reminds the oval probably it is similar to our galaxy and has the diameter about 220 thousand light years and has about 300 milliard stars.
One of the stars that enters the Andromeda constellation was the first discovered star that had several planets in its system. Nowadays scientists know about three planets in it. The planet "b" is the typical hot Jupiter and other two are the giants.
The name of the constellation is connected with the Greek myth according to which Andromeda was the daughter of Ethiopian king Cepheus. She was sacrificed to the maritime monster that tortured the country. But she was saved by Perseus. After her death she turned into constellation.