Pleiades

Pleiades

(plee -ă-deez, plÿ -) (Seven Sisters; M45) A young open cluster about 135 parsecs away in the constellation Taurus. It contains maybe 3000 stars of which at least six are visible to the naked eye: Alcyone, Maia, Atlas, Electra, Merope, and Taygeta; Pleione could once have been brighter. The brightest stars are blue-white (B or Be) and highly luminous, the less bright ones being mainly A and F stars. Gas and dust surrounding the brighter stars reflect the starlight thus producing faint reflection nebulae. Some of these nebulae have been separately cataloged. Thus NGC 1432 is the bright nebula surrounding Maia, while NGC 1435 refers to Tempel's nebula, the nebulosity within which Merope is embedded.

Collins Dictionary of Astronomy © Market House Books Ltd, 2006

Pleiades

[′plē·ə‚dēz]

(astronomy)

An open cluster of a few hundred stars in the constellation Taurus; six of the stars are easily visible to the naked eye.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Pleiades

 

an open, or galactic, cluster in Taurus. Six to nine of the brightest stars of the cluster can be seen with the naked eye. Statistical calculations have established that there are about 540 stars in the cluster, although the number is probably much greater. The brightest star in the Pleiades is Alcyone (η Tauri);

Table 1. The brightest stars In the Pleiades
Name	Visual magnitude
Note: Between Celaeno and Pleione there is a star of magnitude 5.45. and between Celaeno and Asterope I a star of magnitude 5.65
Alcyone(η Tauri)...............................	2.87
Atlas......................................	3.64
Electra ....................................	3.71
Maia......................................	3.88
Merope ....................................	4.18
Taygeta....................................	4.31
Pleione ....................................	5.09
Celaeno....................................	5.46
Asterope I ..................................	5.76
Asterope II ..................................	6.16

like other bright stars in the cluster (see Table 1), Alcyone is a hot star of spectral class B. As shown clearly in long-exposure photographs, the bright stars of the Pleiades illuminate surrounding sections of the large dust nebula within which the entire cluster is located. The cluster has a diameter of 15 parsecs, or about 49 light-years. All the stars of the cluster move through space along nearly parallel paths.

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Pleiades

 

in Greek mythology, the seven daughters of Atlas and of the Oceanid Pleione. According to one variant of the myth, the hunter Orion met the Pleiades and for several years sought their love until Zeus turned both the Pleiades and Orion into constellations. Even in the sky, Orion cannot overtake the Pleiades. Metaphorically, the term refers to a group of outstanding poets or political or military leaders. Examples are the Alexandrian Pleiad of the third century B.C., the French Pléiade of the 16th century A.D., and the Pushkin Pleiad of the 19th century, all composed of poets.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.