asterism

From Ancient Greek ἀστερισμός (asterismós, “group of stars”), from ἀστήρ (astḗr, “star”).

• (UK) IPA^(key): /ˈastəɹɪzəm/

asterism (plural asterisms)

1. (astronomy) An unofficial constellation (small group of stars that forms a visible pattern).

   The Big Dipper, Summer Triangle, and Orion's Belt are asterisms.

   • 1825, Geo G. Carey, Astronomy, as it is known at the present day, London, p. 66 f.:

     Of the constellations, or asterisms. [...] It therefore became necessary to adopt a more general method of distinguishing them. This was accomplished by portioning out the heavens into imaginary figures, of men, birds, fishes, &c. called Constellations or Asterisms.

   • 2007, Matilde Battistini and Rosanna M. Giammanco Frongia (translation from Italian into English), Astrology, Magic, and Alchemy in Art, page 60:

     Like Pisces and Capricorn, Aquarius is located in that part of the sky known as "Astral Sea," a region inhabited by water asterisms such as Eridanus, Cetus (the Whale), and the Dolphin.

2. A rarely used typographical symbol (⁂, three asterisks arranged in a triangle), used to call attention to a passage or to separate subchapters in a book.
3. (mineralogy) A star-shaped figure exhibited by some crystals by reflected light (as in a star sapphire) or by transmitted light (as in some mica).

• aster
• asterisk
• asteroid

• syzygy

• Reitsmas, Ritsemas, St. Maries, maisters, maistres, misrates, semistar, smarties