Star presentation
Transcript: Presented by Lily Onderdonk STARS What are stars made of? What are stars made of? The two dominant elements in stars are hydrogen and helium. These two elements are the lightest, and give stars energy by nuclear fusion, changing hydrogen into helium. Hydrogen & Helium Hydrogen & Helium How are stars formed? How are stars formed? Stars are formed in nebulas. Nebulae are huge interstellar clouds of dust, hydrogen, helium, and a plethora of other gasses. Before they mature, stars are protostars. They become protostars when the gasses in the nebula start to break down. Nebulae Nebulae Different kinds of stars Different kinds of stars Stars come in many sizes and colors. The hottest stars are blue while the coldest stars are red. Stars can also be white and yellow, and even purple, green, and orange. Star Colors Star Colors A lot of the stars that are visible to us are double stars, but since they are so far away, we can see them as one star. Double Stars Double Stars Stars can also be found in star clusters. There are two types of star clusters. One type is an open star cluster, which is a group of hundreds of young stars from the same nebula. Another type is a globular cluster, which is a group of thousands of old stars, crowded together. Star Clusters Star Clusters Stars can be HUGE and tiny. the largest star known to us is named UY Scuti, while the smallest star is named EBLM J0555–57Ab, which is about the size of Saturn. Star size has nothing to do with brightness, the brightest star visible to us is Sirius, a white star which is bigger than the sun. Star Sizes Star Sizes The Sun The Sun Our sun is a medium sized, single yellow star, which makes up about 99.9% the mass of our entire solar system. The sun is considered a G2 dwarf star. Other than our sun, it would take us light years to reach other stars. The closest star to our solar system, other than the sun, is Alpha Centauri, and would take 4 light years to reach it. A light year is a not a measure of time, but a distance, specified by how far light can travel, which is 6 trillion miles How far away are stars? How far away are stars? Stars die when they run out of hydrogen to burn. Larger stars have shorter life spans than smaller stars because they burn hydrogen quickly. Since a star like our sun is smaller, it can continue to burn it's fuel for around 10 billion years, and then explode into a supernova. When a star explodes, it can expand to long distances, consuming all celestial bodies closest to it. In about 5 billion years when our sun explodes, it will consume Mercury, Venus, and maybe even Earth. Supernovas happen when a star depletes iit's fuel, and some of the star's mass will go to the core, making it so heavy that it can't endure it's own gravity. Star Death Star Death Angelo, JR., Joseph A. Facts On File Science Library. Facts On File, Inc. “Ask an Astronomer.” Cool Cosmos, coolcosmos.ipac.caltech.edu/ask/205-What-are-stars-made-of-. By: Sue French September 7, 2017 Comments 0, et al. “Double Stars and Binary Stars in Space.” Sky & Telescope, www.skyandtelescope.com/observing/celestial-objects-to-watch/double-stars/. Crockett, Christopher. “What Is a Light-Year?” EarthSky, earthsky.org/space/what-is-a-light-year. Dockrill, Peter. “Astronomers Just Discovered The Smallest Star Ever Known to Science.”ScienceAlert, www.sciencealert.com/astronomers-have-discovered-the-smallest-star-known-to-science. Fusion in Stars - Zoom Astronomy, www.littleexplorers.com/subjects/astronomy/stars/fusion.shtml. Hesse, Brendan. “Want to Feel Really Small? Meet UY Scuti, the Largest Star in the Universe.” Digital Trends, 4 Apr. 2017, www.digitaltrends.com/cool-tech/uy-scuti-everything-to-know-about-biggest-star-in-the-universe/. Knapp, Brian J., and David Woodroffe. Science Matters! Grolier Educational, 2003. May, Sandra. “What Is a Supernova?” NASA, NASA, 1 June 2015, www.nasa.gov/audience/forstudents/5-8/features/nasa-knows/what-is-a-supernova.html. Pasachoff, Jay M., et al. Astronomy. Pearson, 2009. “Protostar COSMOS.” Centre for Astrophysics and Supercomputing, astronomy.swin.edu.au/cosmos/P/Protostar. Temming, Maria. “How Do Stars Die and How Long Do Stars Live?” Sky & Telescope, 27 Apr. 2017, www.skyandtelescope.com/astronomy-resources/how-long-do-stars-live-stars-die/. “The Jovian Planets.” Planets of the Solar System, earthguide.ucsd.edu/virtualmuseum/ita/08_1.shtml. Ventrudo, Brian. “Profile.” One Minute Astronomer, 23 Dec. 2008, oneminuteastronomer.com/708/star-colors-explained/. Williams, Matt. “Nebulae: What Are They And Where Do They Come From?” Universe Today, 24 Dec. 2015, www.universetoday.com/61103/what-is-a-nebula/.Stars.” NASA, NASA, science.nasa.gov/astrophysics/focus-areas/how-do-stars-form-and-evolve. Bibliography Bibliography Thanks for listening!!