No Thanks, I Don't Want To Donate a Paper

554 WordsApr 8, 20123 Pages
Definitions: STAR- A star, quite simple, is a burning ball of gas. It’s shaped like a sphere, and held together by its own gravity. Their life span varies on their size, but a star the size of our Sun will live for roughly 10 billion years, and a star that weights 20x as much only lives for 10 million years. GALAXY- A galaxy is a large system of stars that are joined together by gravity. The galaxy also includes nebulae, planets, stellar remnants and many other basic elements, including hydrogen and helium. They also consist of a substance that is called dark matter, which is a poorly understood substance that is believed to surround every galaxy and accounts for much of its mass. NEBULA- A nebula (which in Latin means ‘cloud’) is an interstellar cloud of dust, hydrogen, helium and other ionized gases. There are many types of Nebula, and some stars have nebulas around them when they approach the final stages of their lives. CONSTELLATION- A constellation is a group of stars that appear close to each other, as viewed from Earth. Most of them are not actually anywhere close astronomically, but they appear like they’re close in the sky. PLANETARY NEBULA- A planetary nebula is a large cloud of gas, which previously expelled from a central star. It forms when a star can no longer support itself by fusion reactions in its centre. WHITE DWARF STAR- A white dwarf star is what stars like the Sun become after they have used all of their nuclear fuel. Near the end of their nuclear burning stage, stars like the Sun expel most of their outer material, creating a planetary nebula (see above). Only the core of the star remains. BLACK DWARF STAR- A black dwarf star is a white dwarf star that has cooled down to a temperature that matches the temperature of the cosmic microwave background, making it invisible. However, unlike red, brown and white dwarf stars, black

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