Located in the constellation Taurus, the open star cluster Pleiades
(M45) consists of over 500 stars, of which only six are visible to the bare
eye, as mentioned earlier in this node. The Pleiades is probably the best
visible and most easily recognized star cluster to the naked eye. In the night
sky, the whole of Pleiades cover an area approximately four times that of a
full moon, and they are at a distance of about 380 light years. Without a telescope,
they can appear a bit dim and with a telescope one might see a blue-ish haze
surrounding them, which is because they are still young and surrounded by the gas clouds that gave
birth to them.
The stars are really a cluster, and not just an optical illusion of stars
that happen to appear in the same area. It was discovered in mid 19th century
that the stars have no apparent motion relative to each other, and
therefore is really a real cluster of stars that were born together. Recent
calculation show that they are about 100 million years old, and that they will
remain a cluster for another 250 million years before they will live on as
The legends in Greek Mythology have it that they were seven sisters, the
daughters of Atlas and Pleione. One day whilst walking in the woods, the
great hunter Orion lay eye upon them and started chasing them. Only mighty
Zeus could rescue them, and he did so by turning them into doves that could
fly away into the sky. In the night sky, you can still see them chased by Orion,
which is just nearby. Luckily they are protected inside the bull Taurus, which
is one of the forms that Zeus take. The faintest of the sisters, Asterope, is actually a
In Japan the cluster is called Subaru, after which the car manufacturer
with seven stars in its logotype is named.
As a comment to Gorgonzola's writeup, one can even today see 9 or even 12
stars under perfect conditions and with good eyes. In 1579 astronomer Moestlin
accurately drew a map with 11 stars of the Pleiades in it, and this was before
the first telescopes were built.
This is how the seven sisters and their parents are located with respect to each other:
Electra o O o Pleione
Celaeno . Alcyone
Several sources used, most notably SEDS, seds.org.