New Zealand Māori have used the heliacal rising of the Open Cluster the Pleiades. Māori give the name Matariki to this cluster only in about June each year when it is connected to the Māori New Year (more below). This clearly visible cluster has been significant in many cultures and mythologies throughout the world.
Not only is it a beautiful and distinct object in the night sky, in which on a clear night seven or more individual stars can be seen with the naked eye, but it also lies close to the ecliptic, in the constellation Taurus, and can be seen both from northern and southern latitudes most of the year.
The Pleiades, also known as Messier object M45, contain more than 3000 stars. The Open cluster is at a distance of about 400 light years, and is 13 light years across.
Mousover images of the Pleiades
|Visible light image by John Lanoue.
It shows reflection nebulosity of an inter-stellar dust cloud that the Pleiades are passing through.
|Left mouseover image in Infrared by Spitzer Space telescope, NASA, emphasizing the dust cloud.||Right mouseover image in X-ray by ROSAT Space telescope, NASA.
The brightest objects in X-rays are not the brightest visible objects.
In Greek mythology, Atlas and Pleione have seven daughters: Maia (eldest), Electra, Taygete, Alcyone, Celaeno, Sterope (aka Asterope), Merope (youngest). The seven sisters were fancied by the great hunter Orion. He pursued them for seven years, until Zeus saved them by transforming the seven sisters into doves, placing them among the stars. In the sky Orion continues to pursue them for eternity.
|The twelve brightest stars in M45|
|Alcyone||Eta / 25 Tauri||2.90|
|(A)sterope 1||21 Tauri||5.80|
Under very clear conditions about 12 stars are visible with the unaided eye, but generally this will be about 9 or less.