Galaxies

Galaxy: a large grouping of stars

Photo Credit: http://pixabay.com/en/centaurus-a-ngc-5128-galaxy-11190/

Types of galaxies that we will study:

● Spiral● Barred● Elliptical

Photo Credit:http://en.wikipedia.org/wiki/Whirlpool_Galaxy

Spiral Galaxies● Flat pinwheel rotating

around center bulge● 1-3 spiral arms● Arms contain

interstellar material● New stars form in arms● 10-20% dust and gas

Photo Credit: http://en.wikipedia.org/wiki/Spiral_galaxy

Barred Galaxies● Arms wind away from

a central bar, rather than from a central bulge

● Type of spiral galaxy

● The Milky Way is a Barred Spiral galaxy

Photo Credit: https://www.flickr.com/photos/hubble-heritage/3200045708/

Elliptical Galaxies● Stars orbit around mass

in random matter● Slow rotation● Less gas and dust● Very little star formation● Dominated by older stars

Photo Credit: https://www.flickr.com/photos/badastronomy/3110808117/