Constellations are patterns of stars in the night sky. The shapes they seem to make were given names in ancient times, and many of these names are still uses today. The stars that make up constellations are not really close to each other.
Sometimes the stars that look closest are really far apart- they just happen to be I line with each other and so look like a group when viewed from Earth.
In the constellation Corona Borealis there is a star that sometimes dims when tiny black particles hide it from view. North American Indians tested warriors' eyesight by seeing how many stars of the Pleiades they could spot!
