The Pleiades (Seven Sisters) and Coins

 

The Pleiades are an asterism, or a pattern of stars, as well as an open star cluster, made up of more than 1,000 stars. They are located in the constellation Taurus and are about 410 light-years from Earth. Also known as the "Seven Sisters" and Messier 45 (M 45). 

                       

Julia Domna Augusta, AD 193-217, Denarius, struck under Septimus Severus AD 194-195.

They derive their name from Greek legend in which they represent the daughters of the ocean nymph Pleione. In Hindu astrology, this is known as Kritika star cluster and is the third of the 27 Naksatra (constellations).

                     

 Image of the Pleiades from the Digitized Sky Survey

As an open cluster, the stars in the Pleiades were all born around the same time from a gigantic cloud of gas and dust. The brightest stars in the formation glow a hot blue and formed within the last 100 million years. They are extremely luminous and will burn out quickly, with a life span of only a few hundred million years. Scientists estimate that the entire cluster is no more than 150 million years old, and possible as young as 75 million. 

                       

         Locating the Pleiades

 

To find the Pleiades, you can start by locating the famous constellation Orion, the hunter. Draw a line using the three stars in Orion's belt and then follow it upwards past his bow. The Pleiades is visible everywhere around the world, with the exception of the Antarctic Circle. In both hemispheres, the asterism is visible from October to April, and is visible all night in November and does not require any special equipment to view. However, while most people see six stars upon first glancing at the Pleiades, after a while one could observe up to 14. 

                       

Pleiades depicted in various civilizations.

  

Many different cultures have different beliefs associated with Pleiades. The importance of this asterism is evident in northern Europe, on the Nebra sky disc (found buried on the Mittelberg hill near Nebra in Germany. It is a bronze disc around 30 cm in diameter and weighs 2.2kg), dating around 1600 BC, and is represented besides the sun and the Moon. 

                     

The Nebra sky disc, 1600 BC. The cluster of seven dots in the upper right portion of the disc, believed to be Pleiades.

  

It is also this asterism that indicates the beginning of the ancient calendars. The M45 group played an important role in ancient times for establishment of calendars due to the combination of two elements. The first, which is still valid, is its unique and perfectly identifiable aspect on the celestial vault near the ecliptic. The second, essential for the Ancients, is that in the middle of the 3rd century millennium BC, this asterism marked the vernal point.

                       

Orion and Pleiades as seen in the sky.

 

In ancient India, in the Atharvaveda, compiled around 1200-1000 BC, the first nakshatra (Sanskrit name for lunar stations) which is called ''Kritika". In Mesopotamia, the MULAPIN compendium, the first known Mesopotamian astronomy treatise, discovered in the library of Assurbanipal, and dating to 627 BC, presents a list of gods who stand on ''the path of the moon''. In Greece, this is a group whose name is probably functional before having a mythological meaning. They represent Seven Sisters.   In ancient Arabs, they began their old parapegma type calendar, that of the anwa, with M 45 under the name of al-Turayya. 

                       

Galileo's drawings of the Pleiades star cluster from the Siderius Nuncius.

In Hinduism, the Pleiades are known as Krittika and are associated with the war god Kartikeya. Hindus celebrate the first day (new moon) of the month of Kartik as Diwali. In Tamil, they are referred to as the six wives of the seven rishis, the seventh being Arundhati, wife of Vasistha which relates to the star in Ursa Major. The six wives fell in love with Agni, hence the name Pleiades (star of fire). Pleiades are also mentioned three times in the Bible. 

                       

Seven sisters, on an inscription on seal from Harappa.

Chinese call them Quechua, Japanese call them Subaru, the Maya and the Kiowa. Hawaiians call them Makali, the Achaemenid Empire called them Parvin. Ancient Egyptians have used the names " Followers'' and '' Ennead'' in the prognosis texts. Tuareg Berbers of northern Sahara call the Pleiades Cat ihed (pronounced shat ihed) or ahad, meaning ''daughters of the night''.  The folklore of all the regions of the world including the Indigenous people have stories of the Pleiades.

Pleiades on Coins

                      

Hadrian, Denarius, Rome, 126-127 AD, weight 3.5 gm, Obverse: laureate head of Hadrian, with drapery on shoulder, Reverse: Crescent and seven stars. 

                         

Julia Domna, Augusta, AD 193-217, weight 2.8 gm, Emesa mint, struck under Septimius Severus, Obverse: Draped bust right, Reverse: Crescent and seven stars.

                          

Lucretius Trio, Rome 76 BC, Obverse: Bust right, Reverse: Crescent moon and seven stars.                    

                         

Second century AD, weight 12.9 gm, silver, Dia 24.2 Obverse: Head of Zeus, Reverse: Rider riding on the right, below Triskeles, above, seven sisters star.

                         

Julia Domna, Denarius, Emperor Septimius Severus, 27 BC-395 AD, year 193-196 AD, Silver, weight 2.8 gm, Obverse: Bust of Julia Domna, right, unabridged legend, Lulia Domna Augusta, Reverse: Crescent with seven stars above, unabridged legend, Saeculi Felicitias.          

                          

Septimius Severus, AD 193-211, Denarius, weight 2.2 gm, Obverse: Laureate head right, Reverse: Seven stars above the crescent with horns up.

                         

Australia, Elzabeth II, 1952-2022, Non-Circulating Coin, One Dollar, silver, weight 15.0 gm, Commemorative issue, Obverse: Crowned portrait of HM Queen Elizabeth II facing right, wearing the George IV State Diadem and the Coronation Necklace, Reverse: The Seven Sisters running and jumping from right to left in the bottom half of the coin, Aboriginal dot painting of the Pleiades star cluster in the top colourised half of the coin. 0.999 Ag. Canberra mint 1965- date.

Pleiades

Pleiades on Coins