Heptagram

{{Short description|Star polygon with 7 sides}}

{{redirect|Elven star|the novel by Margaret Weis and Tracy Hickman|Elven Star}}

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{{Regular polygon db|Regular star polygon stat table|p7/2}}

{{Regular polygon db|Regular star polygon stat table|p7/3}}

{{Star polygons}}

A heptagram, septagram, septegram or septogram is a seven-point star drawn with seven straight strokes.

The name heptagram combines a numeral prefix, hepta-, with the Greek suffix -gram. The -gram suffix derives from γραμμῆ (grammē) meaning a line.[https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Dgrammh%2F γραμμή], Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus

Geometry

In general, a heptagram is any self-intersecting heptagon (7-sided polygon).

There are two regular heptagrams, labeled as {7/2} and {7/3}, with the second number representing the vertex interval step from a regular heptagon, {7/1}.

This is the smallest star polygon that can be drawn in two forms, as irreducible fractions. The two heptagrams are sometimes called the heptagram (for {7/2}) and the great heptagram (for {7/3}).

The previous one, the regular hexagram {6/2}, is a compound of two triangles. The smallest star polygon is the {5/2} pentagram.

The next one is the {8/3} octagram and its related {8/2} star figure (a compound of two squares), followed by the regular enneagram, which also has two forms: {9/2} and {9/4}, as well as one compound of three triangles {9/3}.

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{7/2}

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{7/3}

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{7}+{7/2}+{7/3}

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7-2 prism

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7-3 prism

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Complete graph

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7-2 antiprism

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7-3 antiprism

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7-4 antiprism

Uses

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=Flags and heraldry=

File:Coat of arms of Georgia (1918–1921; 1990–2004).svg|Former Georgian coat of arms, 1918–1921, 1991–2004

File:Flag of Occitania (with star).svg|The seven-pointed star of the Felibritge on the Occitan flag.

File:Flag of Jordan.svg|The Jordanian flag, bearing the star that symbolizes Al-Fatiha

File:Flag of Hokkaido Prefecture.svg|Symbol of Hokkaido

File:Emblem of Samarkand.svg|Coat of arms of Samarkand

File:Commonwealth_Star.svg|Commonwealth Star as the crest of Coat of Arms of Australia

File:Flag of Cook County, Illinois.svg|The flag of Cook County, Illinois, adopted in June 2022 and taking design cues from the Flag of Chicago, its county seat

File:CHE_Thun_Flag.svg|The coat of arms and flag of Thun Switzerland

= Law enforcement =

File:Seal of the California Highway Patrol.svg|Seal of the :California Highway Patrol

=Religious and occult symbolism=

File:Babalon seal.png

  • The heptagram became a traditional symbol for warding off evil in Catholicism.
  • The symbol is also used in Kabbalist Judaism.
  • The heptagram is used in the symbol for Babalon in Aleister Crowley's occult system Thelema.
  • 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 septegram. The second heptagram is a symbol of magical power in some pagan spiritualities.
  • In alchemy, a seven-sided star can refer to the seven planets which were known to early alchemists, and also, the seven alchemical substances: fire, water, air, earth, sulphur, salt and mercury.
  • In astrology. For example, the planetary hours, from which comes the names of the days of the week.
  • In Polynesia, the seven-pointed star is used often in imagery, basket making, tattoos, and is considered to be a symbol of Kanaloa, the first Polynesian navigator.{{Cite web|url=https://www.huna.org/|title=HUNA INTERNATIONAL - Your best resource for Huna Knowledge and Practice|website=www.huna.org}}{{Cite book|isbn = 0835600025|title = Children of the Rainbow: A Book Concerning the Religion, Legends, and Gods of the Natives of Pre-Christian Hawaii|last1 = Melville|first1 = Leinani|year = 1969| publisher=Theosophical Publishing House }}
  • The seven-sided star is an important symbol of the Cherokee people of southern Appalachia, representing the seven clans of the Cherokee and the sacred number seven.

= Variants =

File:Heptagram.svg|Interlaced; equivalent to the 71 knot

See also

References

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Bibliography

  • Grünbaum, B. and G.C. Shephard; Tilings and patterns, New York: W. H. Freeman & Co., (1987), {{ISBN|0-7167-1193-1}}.
  • Grünbaum, B.; Polyhedra with Hollow Faces, Proc of NATO-ASI Conference on Polytopes ... etc. (Toronto 1993), ed T. Bisztriczky et al., Kluwer Academic (1994) pp. 43–70.
  • John H. Conway, Heidi Burgiel, Chaim Goodman-Strauss, The Symmetries of Things 2008, {{ISBN|978-1-56881-220-5}} (Chapter 26. pp. 404: Regular star-polytopes Dimension 2)