Galaxy

“Thoughts are like burning stars, and ideas, they flood, they stretch the universe.”

― Criss Jami

By: Gurneet Gill and Charndeep Chattu

By the end of 10.2• You will learn….

• The 3 types of Galaxies

• The 2 types of Clusters

• The differences in Galaxies

• About Edwin Hubble/ Hubble Space Telescope

What’s a Galaxy?• A Galaxy contains gases, dust, and billions of

stars that are held together by a gravitation attraction.

• Earth is in the Milky Way which is a galaxy.

Differences in Galaxies • Have different sizes, masses, colours, brightness,

and speed of spin. • Number of stars, type of stars, and amount/type of

gas and dust make up a galaxy. • Some grow larger while others stay small.• More a galaxy spins the flatter it will be.

Types of Galaxies (cont.)

• There are 3 common types of Galaxies: Spiral Galaxy• Has many long ‘arms’ spiraling out of a center core.• Center core is made of old stars. • From a side view spiral galaxies look flat and long.

Spiral Galaxy Side View of Spiral Galaxy

Types of Galaxies (cont.)

Elliptical Galaxy• Range in shape from a perfect sphere to a

stretched out sphere • Contain some of the oldest stars in the universe.

Types of Galaxies Irregular Galaxy• Looks like a bunch of random stars close by. • Composed of new stars and adult stars.

Clusters (cont.) • Many galaxies contain 2 types of distinct

formations of stars: • Globular Cluster • made of about 1 million stars held together by

gravity in a spherical shape.

Clusters• Open Cluster: • Made of a few hundred-few tens of thousand of

stars.

Edwin Hubble • He was an astronomer.• In 1925 he thought he was looking at a bright

nebula but he was actually looking at another galaxy.

• Astronomers estimate there is about 125 billion. galaxies.

Above is a nebula (made of dust and gas). Some nebulae is where stars are born.

Hubble Space Telescope

• Transmits images of galaxies to earth.

Above is a picture taken by a Hubble telescope.

Where are we in the Milky way?

• We’re in the outer arms of a spiral galaxy. • Our solar system is approximately 28,000 light

years away from the center.• A light year is the distance that light can travel in 1 year.

5 QUESTIONS (cont.)• 1.

Is the picture above a ….

Elliptical GalaxyIrregular GalaxySpiral Galaxy

5 QUESTIONS (cont.)• 2.

Name the above picture ..

a) Globular clusterb) Open clusterc) Irregular galaxy

5 Questions • 3. Who is Edwin Hubble?

• 4. Where is our Solar System located in the Milky Way?

• 5. What is a light year? Define and give an example.

Answers • 1. a. Elliptical galaxy • 2. b. Open Cluster • 3. Answers may vary. Edwin Hubble was an

Astronomer who discovered there’s more than one galaxy.

• 4. The solar system is located in the outer arms of a spiral galaxy.

• 5. A light year is the distance light travels in one year. Ex: 28,000 light years.

Bibliography• http://starchild.gsfc.nasa.gov/docs/StarChild/questions/

question19.html• http://www.spacetelescope.org/news/heic0602/• http://www.goodreads.com/quotes/tag/galaxy• http://learnaboutastronomy.weebly.com/different-types-

of-galaxies.html• http://www.eso.org/public/images/eso9845d/• http://photo.net/photodb/photo?photo_id=5730534• http://www.brighthub.com/science/space/articles/64966

.aspx• http://apod.nasa.gov/apod/ap971114.html• http://en.wikipedia.org/wiki/Globular_cluster• http://apod.nasa.gov/apod/ap000112.html

Bibliography (cont.)• http://en.wikipedia.org/wiki/File:Crab_Nebula.jpg• http://

scienceworld.wolfram.com/biography/Hubble.html• http://

novaonline.nvcc.edu/eli/evans/his135/Events/Sputnik57/chronology.html

• http://www.universetoday.com/18256/where-is-the-sun/

• http://www.edwinhubble.com/• BC Science 9 textbook and Workbook • THANK YOU!