Discovery history of Milky Way

The system of stars is popular called the Milky Way, but the name is more properly restricted to the luminous band stretching across the sky. The name is translation of the Latin Via Lactea; the Greek name was ‘Galaxies’.

It was only in the 1920s that astronomers realized that many of the fuzzy patches revealed by their telescopes were indeed distant assemblages of star that is galaxies.

It seems that Greek philosophers Anaxagoras (500-428 BC) and Democritus (450-371 BC) were the first to propose that the Milky Way was made up of stars.

By 13th century, Nasir al-Din al-Tusi identified the Milky Way as a collection of stars, an observation not confirmed in the West until the work of Galileo.

In 1610 in his ‘Stellar Herald’ Galileo Galilei described his astonishing discoveries: ‘The Milky Way is an accumulation of countless stars’.

Edward Emerson Barnard photographs the Milky Way in 1895. He notes that dark patches are too numerous to be empty space but must represent dark clouds of interstellar.

Originally it was believed that the sun lay in the center of the Galaxy. This was assumed by Herschel and also by the Dutch astronomer Jacobus Cornelius Kapteyn, who carried out a detailed investigation. However, in 1917, Harlow Shapley proved that this is not so.

Bertil Lindblad demonstrates that the motions of stars called ‘star streaming’ by Kapteyn in 1905 can be explained as being due to rotation of the Milky Way galaxy.

In 1919, Harlow Shapley claimed that the globular start clusters lay in a great cloud about the center of the galaxy but he called the Milky Way a metagalaxy and envisioned it as a swarm of lesser systems.
Discovery history of Milky Way