1. Our Universe and Galaxies

2. Universe Solar System (Solar System) Star (Sun)
The parts of our Universe from largest to smallest
Universe
Galaxy (Milky Way)
Solar System (Solar System)
Star (Sun)
Planet (Earth)

3. What makes up galaxies?
Stars and star clusters (billions or even trillions!)
Nebulas – giant clouds of gas and dust where new stars can form
Black Holes – the center of all spiral and elliptical galaxies

4. Spiral (or disc-shaped) Galaxy
Andromeda Galaxy
Has a large bulge in the center with spiral arms traveling around
Contains old and new stars
Ex. Andromeda Galaxy and our Milky Way Galaxy

5. Spiral galaxies
Located in the constellation of Andromeda, the Princess, the Andromeda Galaxy is a large spiral galaxy very similar to our own Galaxy, the Milky Way. It is over 65,000 light-years in diameter and approximately 2.2 million light-years in distance. The area shown in this image is quite large on the sky, covering about five times the area of the full Moon.
NOAO/AURA/NSF Images at and

6. Our Galaxy: the Milky Way
has about 200 billion stars
about 100,000 light-years wide (590 quadrillion miles!)
our Sun is located near the edge of this spiral-shaped galaxy

7. The Milky Way You are here!
From
Astronomers unveiled today what they are calling the best map ever produced of the Milky Way galaxy.
The new view shows our spiral galaxy as it would look face-on to a very distant observer.
The map is based on findings about the structural evolution of the Milky Way. The researchers determined that the Milky Way actually has two fewer major arms than previously believed. In barred spiral galaxies like our own, major arms have a high density of stars, produce lots of new stars, and are clearly connected to the long bar of stars at the galactic center.
By contrast, minor arms have high gas density and presumably less star formation. Scientists had long thought that the Milky Way has four major arms. But the new images show that the spirals are actually made of two major arms and two minor ones. "These major arms plus the bar could be the things that really stand out if you were looking at the Milky Way galaxy from, say, [our nearest galactic neighbor] Andromeda," Benjamin said.
Image at

8. Turn and Talk
What is the name of our galaxy, it’s shape and where is the sun/our solar system located within it?

9. Elliptical Galaxy Massive blobs of stars that have very bright centers
M 87 Galaxy
Massive blobs of stars that have very bright centers
Contain mostly old stars.
Ex. M87 galaxy

10. Elliptical Galaxies
Information on the galaxy on the left at
This image from NASA's Hubble Space Telescope shows the diverse collection of galaxies in the cluster Abell S0740 that is over 450 million light-years away in the direction of the constellation Centaurus.
The giant elliptical ESO 325-G004 looms large at the cluster's center. The galaxy is as massive as 100 billion of our suns. Hubble resolves thousands of globular star clusters orbiting ESO 325-G004. Globular clusters are compact groups of hundreds of thousands of stars that are gravitationally bound together. At the galaxy's distance they appear as pinpoints of light contained within the diffuse halo.
Other fuzzy elliptical galaxies dot the image. Some have evidence of a disk or ring structure that gives them a bow-tie shape. Several spiral galaxies are also present. The starlight in these galaxies is mainly contained in a disk and follows along spiral arms.
This image was created by combining Hubble science observations taken in January 2005 with Hubble Heritage observations taken a year later to form a 3-color composite. The filters that isolate blue, red and infrared light were used with the Advanced Camera for Surveys aboard Hubble.
Information on the galaxy on the right at
JUNE 14, 1995: This Hubble telescope photo mosaic shows a field of distant galaxies.
The brightest object in this picture is NGC 4881 [just above center], an elliptical galaxy in the outskirts of the Coma Cluster, a great cluster of galaxies more than five times farther away than the Virgo Cluster. The distance to the Coma Cluster is an important cosmic yardstick for scaling the overall size of the universe.
Images at and

11. Irregular Galaxy Do not fit in any other class. Large Magellanic Cloud
Contain mostly young stars
may have a distorted shape from interaction with another galaxy
Ex. Large magellanic cloud
Large Magellanic Cloud

12. Irregular Galaxies
About Image on Left:
MARCH 3, 2005: What happens when a galaxy falls in with the wrong crowd? The irregular galaxy NGC 1427A is a spectacular example of the resulting stellar rumble. Under the gravitational grasp of a large gang of galaxies, called the Fornax cluster, the small bluish galaxy is plunging headlong into the group at 600 kilometers per second or nearly 400 miles per second.
1. IS NGC 1427A ACTIVELY FORMING STARS?
NGC 1427A shows numerous hot, blue stars that have been formed very recently, showing that star formation is occurring extensively throughout the galaxy. Within the Fornax cluster, there is a considerable amount of gas lying between the galaxies. When the gas within NGC 1427A collides with the Fornax gas, it is compressed to the point that it starts to collapse under its own gravity. This leads to formation of the myriad of new stars seen across NGC 1427A. The tidal forces of nearby galaxies in the cluster may also play a role in triggering star formation on such a massive scale.
2. WHAT IS THE EVENTUAL FATE FOR NGC 1427A?
NGC 1427A will not survive long as an identifiable galaxy passing through the cluster. Within the next billion years, it will be completely disrupted, spilling its stars and remaining gas into intergalactic space within the Fornax cluster.
About image on right, From
The glowing gas of the interstellar medium (ISM) is the breeding ground for the formation of new stars, and the cemetery where the ashes of dead stars ultimately return.
A team led by astronomers from the National Optical Astronomy Observatory (NOAO) has conducted a new study called the Magellanic Cloud Emission Line Survey (MCELS) that focused expressly on the ISM in the Large Magellanic Cloud and Small Magellanic Cloud—the nearest major galaxies to the Milky Way.
NASA and NOAO/AURA/NSF Images at , , and

13. Galaxy Questions
1. What type of galaxy is the Milky Way? 2. Where is the sun located within the Milky Way? 3. What property is used to classify galaxies? 4. What makes up a galaxy?