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1. Printing Three asterisks in a triangular formation used to call attention to a following passage.
2. Astronomy A pattern of stars that is not one of the traditionally established, named constellations, such as the Big Dipper or the Summer Triangle. Asterisms are often named and may be composed of stars that are members of one or more constellations.
3. Mineralogy A six-rayed starlike figure optically produced in some crystal structures by reflected or transmitted light.

[Greek asterismos, constellation, from astēr, star; see ster- in Indo-European roots.]

as′ter·is′mal adj.


1. (Printing, Lithography & Bookbinding) three asterisks arranged in a triangle (⁂ or the same symbol but upside down), to draw attention to the text that follows
2. (Geological Science) a starlike effect seen in some minerals and gemstones when viewed by reflected or transmitted light
3. (Astronomy) a cluster of stars, which may be a subset or a superset of a constellation
[C16: from Greek asterismos arrangement of constellations, from astēr star]


(ˈæs təˌrɪz əm)

a. a group of stars.
b. a constellation.
2. a property of some crystallized minerals of showing a starlike luminous figure in transmitted light or, in a cabochon-cut stone, by reflected light.
3. three asterisks (⁂ or ⁂) printed before a passage to draw attention to it.
[1590–1600; < Greek asterismós]


Rare. a constellation or small group of unrelated stars. — asterismal, adj.
See also: Astronomy
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.asterism - (mineralogy) a star-shaped figure with six rays that is seen in some crystal structures under reflected or transmitted lightasterism - (mineralogy) a star-shaped figure with six rays that is seen in some crystal structures under reflected or transmitted light
mineralogy - the branch of geology that studies minerals: their structure and properties and the ways of distinguishing them
star - a plane figure with 5 or more points; often used as an emblem
2.asterism - (astronomy) a cluster of stars (or a small constellation)asterism - (astronomy) a cluster of stars (or a small constellation)
natural object - an object occurring naturally; not made by man
astronomy, uranology - the branch of physics that studies celestial bodies and the universe as a whole
constellation - a configuration of stars as seen from the earth
References in periodicals archive ?
As you might suspect from its appearance, NGC 358 is most likely an asterism rather a cluster.
Pictured is the familiar asterism, The Plough, also known as The Big Dipper, in the constellation of Ursa Major, as photographed from my home in County Down, Northern Ireland.
Don't know the difference between an asterism and a constellation?
Martin Steinbach (Steinbach--Gems with a Star, Idar-Oberstein, Germany) covered asterism in gems, noting that 50 gem varieties are known to display asterism when cut as cabochons or spheres, and in 90% of the cases the star is due to rutile 'silk'.
Above Crux is an asterism of four stars making a larger, dimmer cross, the False Cross.
However, locating M51 isn't difficult as it positioned towards the northeast border of Canes Venatici and only a few degrees from the handle of the seven stars that form the famous "Plough" or "Big Dipper" asterism of Ursa Major.
Confucius (Lunyu 2,1) equates the King with the -Northern Asterism," which "occupies its place, while all other stars revolve around it" (Pankenier 2004: 288).
9-4938 is known as an asterism consisting of three magnitude 9 stars slightly more outstanding in a line from north to south.
HE has over 100 winners more on the board but champion trainer Richard Hannon is looking over his shoulder at Sir Henry Cecil, who gave him a nudge in the ribs with an across-the-country treble, with Hannon's son-in-law Richard Hughes bringing home the last leg in his former retainer Khalid Abdullah's colours aboard Asterism in the fillies' maiden.
The radiant is close to Aquarius' 'Water Jar' asterism.
Of all these gems, the most sought are "star" sapphires, that include an asterism, a phenomenon produced by a certain cut which causes the image of a star to appear in the gem.
Spiral-bound to permit this exceptionally practical reference and guide to be laid out flat, special symbols are employed to aid in identifying particular objects, stars, double stars, and asterism.