The Pleiades, sung since ancient times, are the most famous open star cluster in the northern sky. Pascoli’s “Chioccetta” goes to reach its peak of visibility in the sky. And you, how many Pleiades can you spot with the naked eye?
D’Annunzio sang them in his Laudi, the poet Tennyson describes them as “a swarm of fireflies tangled in a silver braid“. They have inspired poets and singers since ancient times. The Pleiades are the most famous star cluster in the night sky.
Thanks to their luminosity, they are easily recognizable – Pascoli makes a reference to it in Il Gelsomino Notturno: “The Chioccetta goes for the blue barnyard with its peep of stars“. And therefore starting from the Homeric poems to the present day, the Pleiades have aroused timeless emotions and songs.
But who are the Pleiades? We discover their main characteristics in mythology and astronomy.
In mythology, the Pleiades are the seven daughters of Atlas and Pleione: Maia, Elettra, Taigete, Asterope, Alcione, Celeno, Merope.
Seven sisters who, again according to Greek myths, had the misfortune of meeting Orion, the hunter. He chased them for five years, until they first turned into doves, then stars, followed by Orion and his dog. According to another version of the myth, the Pleiades died of grief because of their father Atlante and his misfortunes and became stars.
In astronomy the Pleiades, also known as the Seven Sisters or M45, are an open cluster of blue stars (therefore very hot) “housed” by the constellation of Taurus. They are therefore found in the portion of the sky visible in the northern hemisphere between the constellation of Aries and Perseus.
They have been known since ancient times as the open cluster that “embellishes” the constellation of Taurus.
Sung in Homer’s literature, D’Annunzio, their etymology derives the evocative name from “plein” (“navigate”) or from the Greek “pleios” (“many”).
How not to be enchanted, in the clear stelate nights then, in front of the beautiful Pleiades?
In fact, they are the most visible open cluster in the starry sky.
At about 440 light years from us, the cluster is in fact one of the closest to Earth.
It is not surprising then that, starting at 2357 years BC, c.ca were notes, so much to be noted in Chinese annals – they were also known among the Aztecs and the Mayans, who attributed their magical powers.
A complex system of reflection nebulae envelops the cluster. In particular, the stars Merope, Alcione, Elettra and Maia are surrounded by visible reflection nebulae, in excellent observing conditions, through long exposure photographs.
Born about 100 million years ago, they are a relatively young cluster of stars. The visible ones are white, blue and therefore with a very high temperature. With the naked eye it is possible to potentially distinguish up to 14 stars.
It is a beautiful visual exercise, able to distinguish them all without the use of optical instruments!
The cluster is instead made up of more than 1000 other stars, among which about 25% are brown dwarfs, and some white dwarfs.
In the northern hemisphere, star formation is visible in autumn and winter. November turns out to be the best time for the observation of the Seven Sisters, as these reach the peak of height in the sky.
Looking towards the constellation of Orion, it is easy to see, moving the gaze towards Aldebaran and then towards the East, the small luminous conformation. It resembles a miniature of the Ursa Minor. To admire them it is better to use binoculars or a small telescope with a wide field and low magnification, rather than more “demanding” telescopes.
With its apparent magnitude of 2.86, the Alcione star is the brightest of the cluster.
And you, how many of the Pleiades visible to the naked eye, can you distinguish? Let us know in the comments!