Life of Stars By: Hannah Angela G. Dy Guaso Kristen Zakaya C. Zarate What stars are • Huge sphere of hot gas • Produce own light and energy by nuclear fusion. • Fusion happens when lighter elements are forced to become heavier elements. • Energy is created causing the star to heat up and shine. FORMATION OF STARS Clouds of gas and dust are disturbed by the gravity of a nearby phenomena. The disturbance causes clumps to form and draw gas inwards The collapsing clump begins to rotate and flatten into a disc of gas and dust. The disc rotates faster and faster pulling more material inwards creating a hot, dense core called a protostar When the protostar becomes hot enough hydrogen atoms begin to fuse, producing helium and energy After millions of years a bipolar flow erupts from the protostar and blasts away remaining gas and dust Lifespan of stars • mass of star defines its lifespan. • least massive stars live longest • most massive stars in the Universe use fuel up in a few million years • biggest stars last only millions • medium-sized stars last billions • smallest stars can last trillions of years. http://www.universetoday.com/25160/how-long-do-stars-last/ How stars die 1. Helium fuel runs out 2. core will expand and cool 3. Upper layers will expand and eject material that will collect around the dying star to form a planetary nebula 4. core will cool into a white dwarf and then eventually into a black dwarf. References • • • • • • • • • • • http://s.hswstatic.com/gif/how-are-stars-formed-diagram.jpg http://science.howstuffworks.com/how-are-stars-formed.htm http://www.universetoday.com/25160/how-long-do-stars-last/ http://wallpapersus.com/wp-content/uploads/2012/07/stars-5.jpg http://upload.wikimedia.org/wikipedia/commons/4/4a/Cepheus_B.jpg http://nice-coolpics.com/data/media/2/young_stars_emerge_from_orion_s_head.jpg http://d1jqu7g1y74ds1.cloudfront.net/wpcontent/uploads/2010/08/Spitzer-Uncovers-Star-Hatchery.jpg http://www.mrwallpaper.com/wallpapers/space-stars-cosmic-nebula.jpg http://actionforspace.com/wp-content/uploads/2014/04/galaxy-starsspace-wallpapers.jpg http://static.tumblr.com/p4blrwv/EESmdci9n/space_stars_3_1920x1200.j pg http://www.youtube.com/watch?v=4s7vyDLgk3M