The Pleiades (star cluster) reference article from the English Wikipedia on 24-Jul-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Pleiades (star cluster)

Get the latest news from Africa
The Pleiades is an open cluster in the constellation of Taurus also known as Messier 45, or just M 45. This relatively nearby cluster (about 380 light years) is also known as the Seven Sisters although from cities only the five or six brightest stars are visible. From a dark site, ten or more are visible. The stars are surrounded by nebulosity, observable in photographs taken using long period exposures through telescopes with significant apertures. Due to the particular arrangement of the stars in the cluster and its compact appearance, it is often mistaken for the Little Dipper by those with little knowledge of astronomy.

image:pleiades.arp.300pix.jpg
The Pleiades star cluster M45 (visible from both the northern and southern hemispheres) consists of many bright, hot stars that were all formed at the same time within a large cloud of interstellar dust and gas. The blue haze that accompanies them is due to very fine dust which still remains and preferentially reflects the blue light from the stars. The picture shows the cluster with south at the top, as seen in an astronomical telescope.

Visible members of the Pleiades are luminous blue or white stars. The cluster contains hundreds of other stars too faint to be visible to the naked eye. This is a young cluster, with an estimated age of about 100 million years, and a projected life of only an additional 250 million years.


The Pleiades' high visibility in the night sky has guaranteed it a special place in cultures, antique and modern:

Each of the names is assigned to a single star in the cluster. They were mountain-nymphs (Oreads), the daughters of Atlas and Pleione, who are also represented by stars in the cluster; the granddaughters of Iapetus and Clymene, and the sisters of the Hyades, Calypso, and Dione. They committed suicide after the deaths of their sisters, the Hyades.

Alternatively, they were known as the Atlantides.

Pleiades Bright Stars
NameNumberMvTypeCatalog
Alcyoneeta (25) Tauri2.86B7e IIIvdB 23
Atlas27 Tauri3.62B8 IIICed 190
Electra17 Tauri3.70B6e IIIvdB 20
Maia20 Tauri3.86B7 IIINGC 1432
Merope23 Tauri4.17B6 IVNGC 1435, IC 349
Taygeta19 Tauri4.29B6 VCed 19e
PleioneBU (28) Tauri5.09 (var)B8e pCed 19p
Celaeno16 Tauri5.44B7 IVCed 19c
Asterope21 and 22 Tauri5.64/6.41B8e V/B9 V
Sterope18 Tauri5.65B8 VCed 19h

Name: common name
Number: astronomical designation
Mv: visual magnitude
Type: spectral type
Catalog: catalog number of associated nebulosity

See also: La Pléiade, a group of 16th-century French poets

External links and references