The phrase "fixed stars" refers to stars that appear stationary in the night sky, unlike planets which move relative to the background stars. The spelling of this phrase is straightforward: "fixed" is spelled with the letters f-i-x-e-d, while "stars" uses the letters s-t-a-r-s. In terms of pronunciation, "fixed" is pronounced as /fɪkst/, with the "x" representing the sounds "ks". "Stars" is pronounced as /stɑːz/ in British English, and as /stɑːrz/ in American English, with the "a" representing a longer vowel sound.
Fixed stars refers to the countless luminous celestial objects that are observed in the night sky and appear to remain in fixed positions relative to each other, unlike other celestial bodies such as planets or comets that exhibit motion. They are also commonly known as "stellar objects" or simply "stars." These stars are highly distant from Earth and are mainly located outside of our solar system, constituting the visible points of light in the nighttime sky.
In terms of their physical attributes, fixed stars are self-luminous, meaning they emit their own light through a process called stellar nuclear fusion. This process involves the conversion of hydrogen atoms into helium within their cores, generating immense amounts of energy in the form of light and heat. Fixed stars exhibit varying colors, sizes, and brightness levels, which are determined by factors such as temperature, age, and composition.
Fixed stars have been the subject of human curiosity and observation for thousands of years, serving as navigational and divine reference points, as well as sources of artistic inspiration. They have enabled astronomers to study and understand the vastness of the universe and its evolution, helping to unlock the secrets of celestial mechanics, stellar evolution, and the nature of light. The study of fixed stars has also led to the discovery and classification of various types of stars, providing valuable data for the development of astronomical theories and models.
The term "fixed stars" can be broken down into two parts: "fixed" and "stars".
The word "fixed" comes from the Latin word "fixus", which means "firmly placed" or "immovable". In ancient astronomy, the term "fixed stars" was used to distinguish the stars that appeared to maintain a fixed position in the night sky relative to each other. They were contrasted with "wandering stars" or "planets" that moved in relation to the fixed stars.
The word "stars" can be traced back to the Old English word "steorra", which derived from the Proto-Germanic word "sternǭ", meaning "star". This word is thought to have originated from the Proto-Indo-European root "*h₂stḗr", which also gave rise to similar words in other Indo-European languages.