Galaxy
Galaxies range in size from dwarfs with just a few hundred million stars to giants with one hundred trillion stars, each orbiting its galaxy’s center of mass. Most of the galaxies are 1,000 to 100,000 parsecs in diameter and separated by distances on the order of millions of par secs. The word galaxy was borrowed via French and Medieval Latin from the Greek term for the Milkyway, galaxías ‘milky’, named after its appearance as a milky band of light in the sky.
About Galaxy in brief
A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. Galaxies range in size from dwarfs with just a few hundred million stars to giants with one hundred trillion stars, each orbiting its galaxy’s center of mass. Many galaxies are thought to have supermassive black holes at their centers. The Milky Way’s central black hole, known as Sagittarius A*, has a mass four million times greater than the Sun. As of March 2016, GN-z11 is the oldest and most distant observed galaxy with a comoving distance of 32 billion light-years from Earth. Research released in 2016 revised the number of galaxies in the observable universe from a previous estimate of 200 billion to a suggested two trillion or more. Most of the galaxies are 1,000 to 100,000 parsecs in diameter and separated by distances on the order of millions of par secs. For comparison, the Milky Way has a diameter of at least 30,000Parsecs and is separated from the Andromeda Galaxy, its nearest large neighbor, by 780,000 Parsecs. The majority of galaxies are gravitationsally organized into groups, clusters, and superclusters. The word galaxy was borrowed via French and Medieval Latin from the Greek term for the Milkyway, galaxías ‘milky’, named after its appearance as a milky band of light in the sky.
The English term Milky Way can be traced back to a story by Chaucer c. 1380: “See yonder, lo, the Galaxyë, which men clepeth the Milky Wey,For hit is whyt.” The realization that we live in a galaxy which is one of many parallels that was made about the Democritus and other Greek philosophers. For example, Messier is a spiral galaxy having the number 109 in the catalogue of Messier, also having the design of the Messier and Messier catalogues. The Messier catalogue, such as the ICGC, the MCG, the CGCG, and UGCG are well-known galaxies, but appear in more than one or two catalogues under a different number of these catalogues, but each time under different names. The name Milky Way is also used to distinguish it from the other galaxies in our universe, including the Andromeda galaxy, the Magellanic Galaxy, the Whombrero Galaxy, and the Galaxy of the Sun, among many others. It is also a reference to the Greek galaxias, literally ‘milky’, which is also the name of a Greek goddess of the night, and is the origin of the word ‘galaxia’ or ‘ Milky Way’. In Greek mythology, Zeus places his son born by a mortal woman, the infant Heracles, on Hera’s breast while she is asleep so the baby will drink her divine milk and become immortal.
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This page is based on the article Galaxy published in Wikipedia (as of Dec. 06, 2020) and was automatically summarized using artificial intelligence.
