Cassiopeia
Cassiopeia is non-setting constellation of the North hemisphere of the sky. The brightest stars of Cassiopeia make the figure that reminds letters "M" and "W". This constellation has 150 stars that can be seen with the necked eye. 90 stars of this constellation are brighter than 6m. The major part of the constellation is situated in the line of the Via Lacteal and contains many clusters.
The constellation of Cassiopeia includes the asterism that forms the memorable form of the letter "W". It consists of the brightest stars of the constellation.
This constellation also has the star that refers to the class of super giant stars. It is 40 times heavier and about 500 thousand times brighter than the sun. The majority of the time its shinning is unchangeable and is close to 4m. But sometimes it becomes less bright and then the star becomes invisible for the necked eye. The reason for the changes in shinning is emissions of the gases into the space that leads to weakening of the brightness visibility.
The main star of the constellation is the yellow dwarf. It has the satellite that is the little red cold star with the temperature of the surface close to 3 thousand K. the both stars rotate round the general centre of gravitation with the period of 526 years. They are situated close to the sun at the distance of 20 light years.
According to the myth Cassiopeia was bound to the armchair for her boasting. She is made to sit and rotate in this armchair turning upside down. Arabs called the part of the stars of Cassiopeia "the arms of Pleiad".