The heptagram is known among neopagans as the Elven Star or Fairy Star. It is treated as a sacred symbol in various modern pagan and witchcraft traditions. Blue Star Wicca also uses the symbol, where it is referred to as a septagram. The second heptagram is a symbol of magical power in some pagan spiritualities.
Source: Heptagram – Wikipedia
Tim B.
“Medieval alchemists used the seven-pointed star to stand for the seven alchemical metals and their corresponding planets. But it may also stand for the seven colors, the seven musical notes, the seven sisters (Pleiades), or any of the many sacred things that come in groups of seven. In Hermetic Qabalah, the septagram can represent the sphere of Netzach and the corresponding planet of Venus. Aleister Crowley also chose a septagram as the seal of Babalon, the Great Mother and sacred whore of Thelema.
The septagram, because it has an odd number of points, can be traced in a continuous line. Its unbroken form helps give the star its identity as a symbol of Eternity.”
https://www.groveandgrotto.com/blogs/articles/35427009-the-faery-star
Tim B.
http://symboldictionary.net/?p=373