Classifying Galaxies

Edwin Hubble at the 100 inch Telescope

     Edwin Hubble (1889-1953) guides the exposure of a photographic plate at the Newtonian focus of the 100-inch telescope in 1923. With this telescope, Hubble measured the distances and velocities of galaxies, work which led to today's concept of an expanding Universe. According to this profound idea, the Universe began ten to twenty billion years ago with a Big Bang. The receding galaxies that Hubble observed trace the expansion of space from that dense beginning. The telescope is a mechanical masterpiece and was dedicated as an International Historical Mechanical Engineering Landmark on June 20, 1981, by the American Society of Mechanical Engineers, only the fourth such award granted in the United States.

     Edwin Hubble grew up in Wheaton, Illinois, a suburb of Chicago.

                                               For a complete biography, click here.

      Before he went on to become a famous astronomer, Edwin Hubble taught Spanish and physics as well as coached basketball at New Albany High School, Indiana, in 1914. The New Albany High School Yearbook "Vista" was dedicated to him.

     Look at the dedication page of the 1914 NAHS yearbook  to see a picture of Coach Hubble and the winning basketball team, then use the back arrow at the top of your browser to return here.

For more information about Edwin Hubble and his system of galaxy classification click here, then use the back arrow at the top of your browser to return here.

This page last updated December 12, 1997

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Classifying Galaxies

Instructions for Classification

     

Rotating Spiral Galaxy animation by Josh Kennedy

Look at the rotating galaxy and then at the Hubble Tuning Fork Diagram next to it. Edwin Hubble would have classified this galaxy as type Sa. Notice its well defined center and spiral arms.

On the next page, you will have a chance to classify some unidentified galaxies, and use your mouse to place the galaxy images on the Hubble Tuning Fork Diagram. To move the galaxy pictures onto the Hubble Tuning Fork Diagram you will:

• put your mouse pointer on a galaxy image
• hold down the mouse button
• while holding down the button, move your pointer to a spot on the diagram
• release the mouse button

When you release the mouse button, the galaxy image will move to the spot you have selected. If you wish to move it again, you can follow the same directions. When you have finished placing all the galaxy images on the diagram, check your work by clicking on the the Galaxy Guy.

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