50 Fun Facts About The Pleiades

In which constellation are the Pleiades found?

They sit in the bull's northwest corner and, with the Hyades, form the so-called Golden Gate of the Ecliptic.

What is the Pleiades' designation in Charles Messier's catalogue?

It is the Messier object nearest to Earth and an odd inclusion, since nobody could mistake it for a comet.

By what popular name, referring to a family, are the Pleiades also known?

Their myths worldwide almost always explain why only six can easily be seen.

Roughly how far from Earth are the Pleiades?

That is about 136 parsecs, and it makes them one of the nearest star clusters to Earth.

About how many stars does the Pleiades cluster contain?

Only the brightest six or seven are easily visible to the naked eye, though sharp-eyed observers can see up to 14.

What colour are the hot, luminous stars that dominate the Pleiades?

They are young B-type stars formed within the last 100 million years.

What are the reflection nebulae around the brightest Pleiades thought to be?

Rather than leftover birth material, the dust is an unrelated cloud moving at about 18 km/s relative to the cluster's stars.

What is NGC 1435, the reflection cloud around one of the Pleiades, called?

NGC 1432 is the cluster's other catalogued nebula, an HII region.

For roughly how much longer are the Pleiades expected to survive as a cluster?

Gravitational interactions with the galactic neighbourhood will eventually pull it apart.

Which famous stellar nursery did the Pleiades probably once resemble, according to computer simulations?

The cluster is now slowly drifting towards the feet of Orion.

Together with which nearby open cluster do the Pleiades form the "Golden Gate of the Ecliptic"?

In Greek myth the Hyades were the Pleiades' sisters, also daughters of Atlas.

The name Pleiades probably derives from a Greek verb meaning what?

Their heliacal rising marked the start of the Mediterranean sailing season, and the myth of mother Pleione came later.

Around what year did the Pleiades mark the vernal equinox point?

That is why Babylonian star lists put MUL.MUL, "the stars", at the head of the ecliptic.

Which Bronze Age artefact found in Germany carries the earliest known depiction of the Pleiades?

Dated to about 1600 BC, it shows the cluster between the Sun and the Moon and was found by looters in 1999.

What did the Babylonian name for the Pleiades, MUL.MUL, literally mean?

On cylinder seals of the first millennium BC the cluster appears as seven dots.

Under what name are the Pleiades known in Hinduism, associated with the war god Kartikeya?

They were the first nakshatra, or lunar station, in the Atharvaveda; the name means "the Cuttings".

How many times are the Pleiades mentioned in the Bible, under the Hebrew name Kimah?

Each passage, in Amos and Job, also mentions Orion; God asks Job whether he can bind the Pleiades' chains.

What Arabic name for the Pleiades was so famous that pre-Islamic Arabs often just said 'the Star'?

The name lives on in the Thuraya satellite phone system of the United Arab Emirates.

What is the Japanese name for the Pleiades, also used by a car maker?

It comes from a verb meaning "to cluster together", and the eighth-century Kojiki called the group Mutsuraboshi, six stars.

How many stars appear in the logo of the car maker named after the cluster?

They stand for the five companies that merged to form the firm plus the whole, echoing the six visible sisters.

Where is the 8.2-metre Japanese flagship telescope named after the cluster located?

It had the largest monolithic primary mirror in the world from 1998 to 2005.

What do the Māori call the Pleiades?

Their first rising in late June or early July marks the Māori new year.

In which year did New Zealand first observe the Māori new year as an official public holiday?

The celebration had declined in the 20th century before a revival that began in the early 1990s.

According to Māori tradition, whose eyes are the stars of the Pleiades?

Enraged at his parents' separation, he plucked out his own eyes and flung them into the sky.

Who was the first astronomer to view the Pleiades through a telescope?

His sketch of 36 stars appeared in Sidereus Nuncius in March 1610.

How many Pleiades stars did Galileo show in his 1610 sketch in Sidereus Nuncius?

The telescope revealed many stars too dim for the naked eye.

Which English natural philosopher put a chance alignment of the Pleiades at 1 in 500,000 in 1767?

He concluded that the Pleiades and other clusters must be physically related groups.

Which satellite produced a controversially short distance of only 118 parsecs to the Pleiades?

Later Hubble, VLBI and Gaia measurements settled on about 136 parsecs, and the Hipparcos figure is now considered an error.

What distance to the Pleiades does the Gaia Data Release 3 give?

That is with an uncertainty of just 0.10 parsecs.

What is the estimated total mass of the Pleiades cluster?

Fainter, redder stars dominate the mass even though blue giants dominate the light.

Which objects, like Teide 1, may be a quarter of the cluster's population but under 2% of its mass?

They have less than about 8% of the Sun's mass, too little to fuse hydrogen.

Which element, kept by failed stars but burned by normal ones, dates the cluster to about 115 Myr?

It ignites at only 2.5 million kelvin, so even the heaviest brown dwarfs eventually burn it.

Which star is the brightest in the Pleiades?

Eta Tauri is a blue-white giant of magnitude 2.87 and the third-brightest star in Taurus.

Which two stars in the cluster are named after the mythical parents of the sisters?

Their names were formally assigned by Michael van Langren and first recorded by Riccioli in 1665.

Which of the sisters was the eldest and the mother of Hermes by Zeus?

Zeus also fathered children with Electra and Taygete; Poseidon with Alcyone and Celaeno.

Which sister married the mortal Sisyphus and, in some tellings, faded from the sky in shame?

She was the youngest, and her dimness is one explanation for the "lost Pleiad".

Which hunter pursued the sisters until Zeus turned them into doves and then stars?

His constellation is said to chase them across the sky still, and Hesiod has them "flee mighty Orion" as they set.

Whose companions were the seven sister-nymphs in Greek myth?

With the Hyades they also served as nursemaids to the infant Dionysus and were associated with rain.

A Kiowa legend links the origin of the Pleiades to which American landmark?

Seven girls fled a bear and rose into the sky, and the grooves on the tower are the bear's claw marks.

What did the Aztecs call the Pleiades, a Nahuatl word meaning "marketplace"?

According to Anthony Aveni, the Aztec calendar was based on the cluster.

What does the Quechua name for the Pleiades, Qullqa, mean?

The Ukrainian name Stozhary similarly traces back to a word for granary.

What are the Pleiades called in J. R. R. Tolkien's legendarium?

Menelvagor is Tolkien's name for Orion.

Under ideal conditions, up to how many Pleiades stars can a sharp-eyed observer see with the naked eye?

Most people see six or seven; the brightest stars form a shape a little like the Big and Little Dippers.

Roughly what fraction of stars in the Pleiades are estimated to be in binary systems?

The cluster's more than 1,000 confirmed members would grow further if every binary could be resolved.

Whose 1665 book Astronomia Reformata contains the first recorded use of the sisters' names for the stars?

He credited Vicente Mut for naming the seven main stars and Michael van Langren for Atlas and Pleione.

What is the approximate core radius of the Pleiades cluster?

The tidal radius, beyond which stars are stripped away, is about 43 light-years.

Which star in the Pleiades, slightly heavier than the Sun, shows signs of planet formation in its hot dust?

Spitzer and Gemini North infrared images revealed an extraordinary number of hot dust particles around it.

What did pre-colonial Filipinos, who called the cluster Mapúlon, use it to mark?

Hawaiians call the cluster Makali'i and Persians Parvin.

In the Atharvaveda, the Pleiades formed the first lunar station, with a name literally meaning what?

Krittika marked the break of the year before the classic list demoted it to third place.

Hindus celebrate the new moon of which month, named for the Pleiades-linked deity, as Diwali?

The cluster is also associated with the Saptamatrika, the Seven Mothers.