Galaxy Formation K.L. 7th grade Table of Contents ● Title Page ● Materials Needed ● Table of Contents ● Procedure ● Focus Question ● Results ● Introduction ● Conclusion ● Purpose ● Bibliography ● Hypothesis Statement ● Glossary ● Background Information Focus Question How was the Milky Way Galaxy formed? Introduction My science fair this year is about galaxies. I have always been interested in galaxies and space. I wanted to do this project to learn more about galaxies and the people who helped discover them. Purpose The purpose of this project is to find out how the Milky Way Galaxy was created. Hypothesis Statement The Milky Way was formed by star clusters coming together to form the center of our galaxy and as it rotated it flattened out into a disk. What is Astronomy? Astronomy is a branch of science which deals with celestial objects, space and the physical universe. One of the earliest astronomers was in the 2nd century BCE. He was the famous Greek astronomer Hipparchus of Nicaea was first to make a stellar catalogue. What is a Galaxy? A galaxy is a system of stars, dust and gas held together by gravity. Almost all galaxies have a black hole at the center. Galaxies range in diameter from a few thousand to half a million light years. Astronomers measure galaxies by their surface, brightness, fluctuations and their color. One light year is 9,461 x 10 to the 12th power kilometers or about 6 trillion miles. What Types of Galaxies are There? In 1936, Edwin Hubble classified galaxies into four groups. The four types of galaxies are a spiral galaxy, an elliptical galaxy, an lenticular galaxy, and an irregular galaxy. What is a Spiral Galaxy? Over ⅔ of all observed galaxies are spiral galaxies. Spiral galaxies have a flat, thin spinning disk in the center with a central bunch of stars surrounded by spiral arms. The spinning motion, at hundreds of kilometers per second, causes the spiral shape. What is a Elliptical Galaxy? Elliptical galaxies are round and stretch longer along one of its axis’ than the other. Our universes, largest known, contain more than two trillion stars and span 2 million light years. Elliptical galaxies contain older stars, but little dust and other interstellar matter. The stars in an elliptical galaxy orbit around its galactic center in random directions. They are also common in galaxy clusters. What is a Lenticular Galaxy? Lenticular galaxies sit between elliptical galaxies and spiral galaxies. They were named because they resembled lenses. Like spiral galaxies, lenticular galaxies have a thin rotating disk and their center is made up of stars but do not have spiral arms. Like elliptical galaxies they have little dust and interstellar matter. Lenticular galaxies form mainly in populated areas. What is a Irregular Galaxy? Irregular galaxies appear misshapen and lack a distinct form. This is caused by being within gravitational influence of other galaxies. Lenticular galaxies are full of dust and gas and are great nurseries for new forming stars. About the Milky Way Our galaxy's name is the Milky Way. The Milky Way is a barred spiral galaxy. A barred spiral galaxy is a subtype of galaxy. The Milky Way's diameter is about 100,000 light years. The black hole at the center of our galaxy is called Sagittarius A. It has the mass of 4 million suns. The Milky Way was formed by multiple star clusters forming together to form what we know as our galaxy’s core. Over the years the core rotated faster it eventually flattened out into a disk making the Milky Way as we know it now. What is a Dwarf Galaxy? A dwarf galaxy is a galaxy composed of about 1,000 up to several million stars as compared to the Milky Way's 200-4000 billion. There are many possibilities to how dwarf galaxies are formed. One of the possibilities is that gravitational bound collections of gas and stars form during mergers or interactions between two larger galaxies. Dwarf galaxies are low mass and smaller in size to normal galaxies. Dwarf galaxies can be any type of galaxy. Materials Needed 1. A blank canvas 2. Black paint 3. White paint 4. Blue paint 5. Yellow paint 6. Glitter (whatever color) Procedure 1. Paint canvas black 2. Paint a yellow oval shape in the center of the canvas 3. Paint blue lines from the center going around in a spiral motion 4. Add white specs and glitter as needed Results The Milky Way Galaxy was created by star clusters forming together to make the center of the galaxy that then flattened out into a disk shape. Conclusion All the things i learned about the Milky Way and other galaxies was fascinating. I learned about the names of the galaxies and why they’re named that way. I learned about new theories and discoveries that have been made over the years. This project was very fun and exciting. Bibliography 1. Michael Greshko, Galaxies-facts and information, National Geographic, Washington D.C., 4/17/19 https://www.nationalgeographic.com/science/space/universe/galaxies/ 2. 3. Galaxies, Las Cumbres Observatory, Goleta, 12/23/20 https://lco.global/spacebook/galaxies/history-discovery/#:~:text=The%20first%20galaxies %20were%20identified,he%20knew%20were%20not%20comets Bibliography 4. David J. Eicher, How was the Milky Way Formed, Astronomy, 7/1/19 https://astronomy.com/magazine/greatest-mysteries/2019/07/38-how-did-the-milky-way-gala xy-form#:~:text=The%20galaxy's%20core%20lies%2026%2C000,contains%20a%20supermassive %20black%20hole.&text=If%20this%20is%20correct%2C%20the,flattened%20out%20into%20a%2 0disk Glossary Black Hole - A place in space where gravity pulls so much even light can’t escape Axis - An imaginary line about which a body rotates Gravity - The force of attraction by which terrestrial bodies are pulled toward something Diameter - A straight line passing through the center of a circle Equinox - The time when the sun crosses the plane of the earth’s equator, making night and day the same length.