asterism


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asterism

A prominent grouping of stars forming a distinctive shape but not a complete or recognized constellation. The Plough is an asterism within the constellation Ursa Major. Other examples of asterisms are the Sickle in Leo, the False Cross and the Summer Triangle.

asterism

[′as·tə‚riz·əm]
(astronomy)
A constellation or small group of stars.
(optics)
A starlike optical phenomenon seen in gemstones called star stones; due to reflection of light by lustrous inclusions reduced to sharp lines of light by a domed cabochon style of cutting.
(spectroscopy)
A star-shaped pattern sometimes seen in x-ray spectrophotographs.
References in periodicals archive ?
Calendar asterisms were chosen so that they form opposing pairs (cf.
Ken Hewitt-White, a contributing editor for Sky & Telescope, fittingly thinks this asterism "suggests a caterpillar humped-up in mid crawl.
We concluded that this was a natural sapphire that had been diffused-treated to induce its colour and asterism.
5[degrees] further south-west, among a multitude of galaxies, another asterism can be found.
The fifth star of the North Pole asterism is called 'Celestial Pivot' [TEXT NOT REPRODUCIBLE IN ASCII] and the place nearby which lacks stars is called the Vermilion Pole [TEXT NOT REPRODUCIBLE IN ASCII].
If this lovely asterism has a name, I haven't found it yet, so I've taken to calling it the "Fertile Crescent".
0) Dec RT Capricorni Carbon Star 20h17m2 -21[degrees]20 NGC 6908 Nebulosity 20 25 1 -24 48 NGC 6907 Galaxy 20 25 6 -24 49 Asterism Star Group 20 26 7 -24 57 NGC 7099, M 30 Globular Cluster 21 40 4 -23 11 Palomar 12 Globular Cluster 21 46 6 -21 15 NGC 7158 Unknown 21 57 4 -11 36 Object Type Mag Size RT Capricorni Carbon Star 7-11 * NGC 6908 Nebulosity 14 0.
0) Dec NGC 4303 (M 61) Galaxy 12h] +04[degrees]28 21m 9 NGC 4374 (M 84) Galaxy 12 25 1 +12 53 NGC 4406 (M 86) Galaxy 12 26 2 +12 57 NGC 4435 Galaxy 12 27 7 +13 01 NGC 4438 Galaxy 12 27 8 +13 01 3C 273 Quasar 12 29 1 +02 03 NGC 4486 (M 87) Galaxy 12 30 8 +12 23 NGC 4567 Galaxy 12 36 5 +11 15 NGC 4568 Galaxy 12 36 6 +11 14 Jaws Asterism 12 38 5 +11 30 NGC 4594 (M 104) Galaxy 12 39 8 -11 37 IC 972 Planetary 14 04 4 -17 15 Nebula NGC 5634 Globular 14 29 6 -05 59 Cluster Object Mag Size NGC 4303 (M 61) 9.
The densest clump of visible galaxies forms a house-like shape not unlike the asterism that underlies the constellation Cepheus.
5 degrees south to the asterism Alessi J11046-3157--five magnitude 12 to 13 stars in a short string from north to south, with two fainter ones topping the scale to the west (see sketch).