A star with a circle around it, called a pentacle, is used to symbolize harmony, protection, eternity and infinity. It is also used to refer to the cycles of nature and human life.
The circle often circumscribes a five-point star, also known as a pentagram. The five-point star within the pentacle refers to the special significance attached to the number 5. There are five common senses, five digits on each hand and toe and so on. Five is hence seen as being mystical, yet closely connected to humanity. When a circle is drawn around the five-star, it implies that all these special concerns of humanity are enclosed and protected.