Andromeda is our nearest galactic neighbor at 2.5 million light years away. It is twice the size of our Milky Way. Spiral Andromeda contains over 1 trillion stars and 5 billion planets. Forming 10 billion years ago, it is younger than our Milky Way which is 13 billion years old.
The name Andromeda refers to a princess in Greek mythology and the nearby Andromeda constellation. Astronomer Ptolemy in ancient Greece catalogued Andromeda as an unknown celestial object, not aware what galaxies were at the time.
In 1924 American astronomer Edwin Hubble announced he had located Andromeda, calling it an 'island universe' due to its colossal size. He identified it as our 'sister galaxy' and nearest galactic neighbor. Modern astronomers refer to it as M31.
The Pleiadian star cluster is approximately 444 light years from Earth. The word Pleiades comes from the ancient Greek 'plein' meaning 'sail.' It is also known as the Seven Sisters, originating from the Greek myth of Pleione and her seven daughters.
Otberwise known as Messier 45, it is located in the constellation Taurus. Its nine brightest suns are named for the seven sisters of the Greek myth, Alcyone, Electra, Maia, Taygeta, Celaeno, Asterope and Merope, along with their parents Atlas and Pleione.
The brightest star in the cluster is Alcyone which dwarfs our sun and is more than 300 times as luminous. The image below shows our sun at far left and Alcyone at far right. Italian astronomer Galileo Galilei first observed the Pleiades in 1610, his sketch in 2nd photo...