Stars are born amid clouds of dust and swirling winds in our atmosphere. Turbulence within these clouds creates enough gravitational force between the gas and dust that they begin to collapse in on themselves and become denser and hotter within the cloud. The cloud continues to collapse, gathering dust and gas around the hot center called the protostar. (http://science.nationalgeographic.com) Protostars are not hot enough to emit visible light in their early stages, but they do emit infrared. In later stages, protostars emit more visible light, but images taken with visible-light telescopes have difficulty seeing beyond the large masses of dust around the stars if the stars are not very bright. caltech.edu) Stars the size of our Sun are estimated to mature over a period of about 50 million years, or from the initial collapse of the clouds to adulthood. Our sun is expected to remain in this mature phase for about 10 billion years and is estimated to be halfway through its life. Stars come to life from hydrogen nuclear fusions; forming helium deep inside them. The energy moves outward, giving the entity sufficient resistance to the pressure of collapsing under its own weight, and causing it to glow. Some stars shine dimly and others shine brighter or hotter than the sun. Red dwarfs are the smallest stars and shine for tens of billions of years. Hypergiants, the largest stars in the known universe, are a hundred or more times larger than our sun and emit hundreds of thousands of times more energy. That said, their lives last only a few million years, which is much shorter than that estimated for our Sun. Hypergiants were believed to be common in the early universe, but they are... middle of paper... distant . The stars are what we will always look for. Works Cited http://science.nasa.gov/astrophysics/focus-areas/how-do-stars-form-and-evolve/ http://coolcosmos.ipac.caltech.edu/ cosmic_classroom/cosmic_reference/starform.html http ://news.nationalgeographic.com/news/2013/05/130529-how-stars-die-sodium-space-astronomy-science/ http://science.nationalgeographic.com/science/space/universe/stars- article /http://www.astro.wisc.edu/~dolan/constellations/ http://docs.kde.org/stable/en/kdeedu/kstars/ai-colorandtemp.html http://www.bobthealien.co .uk/stardiff.htm http://imagine.gsfc.nasa.gov/ docs/science/know_l1/pulsars.html http://hubblesite.org/explore_astronomy/black_holes/home.html http://imagine.gsfc. nasa.gov/docs/science/know_l2/supernovae.html http://stars.astro.illinois.edu/sow/star_intro.htmlhttp://www-istp.gsfc.nasa.gov /istp/outreach/workshop/thompson /facts.html
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