Our Universe

Universe TEKS 8.8 A: DESCRIBE components of the universe including stars, nebulae and galaxies, and use models as the Hertzsprung-Russell diagram for classification.

All space and the matter space contains Universe All space and the matter space contains The Big Bang Theory is one theory of the formation of the Universe. It states that the universe began with a tremendous explosion http://hrw.com

Universe contains: Galaxies Stars Nebulae Quasars Comets

Galaxies There are four main types of Galaxies Spiral Elliptical Irregular Lenticular

Galaxies Spiral Characterized by a bulge at the center and spiral arms Spiral shape is caused by the rotation of the galaxy http://hrw.com

Galaxies Elliptical Characterized by a very bright centers and very little dust and gas Appear elongated or spherical and are basically massive blobs of stars Composed of mostly old stars http://hrw.com

Galaxies Irregular Galaxies that do not fit into any other class As their name indicates they have irregular shapes http://hrw.com

Galaxies Lenticular Galaxies with a central bulge or bar with short arms, if any are present http://hrw.com

Stars Composition Brightness Temperature Mass Life Cycle

Stars Composition Made up of different elements in the form of gasses When viewed through a spectrograph the specific gasses can be identified through an absorption spectrum which is a continuous spectrum with dark lines where less light gets through.

Stars Illustrating the relationship between temperature and brightness http://hrw.com

Stars Mass Single most important determiner of a stars life cycle High Mass Low Mass http://www.enchantedlearning.com/subjects/astronomy/stars/lifecycle/

Stars Illustrating the relationship between mass and star life time – smaller stars have longer lives! http://hrw.com

Illustrating the relationship between mass and brightness Stars Illustrating the relationship between mass and brightness http://hrw.com

Nebula Latin for “Cloud” Giant clouds of gas and dust Where new stars are formed Found in spiral galaxies Not found in elliptical galaxies http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-astro-nebula.html

Quasars The most powerful energy source in the universe May be the core of young galaxies forming Among the most distant objects in space from Earth http://hubblesite.org/newscenter/newsdesk/archive/releases/category/galaxy/quasar_active%20nucleus/

Comets http://www.nasa.gov/audience/forkids/home/F_SC_comet.html A comet is made of dirty ice, dust, and gas. When a comet gets close to the Sun, part of the ice starts to melt. This lets the dust and gas out. Solar winds then push them away from the comet. This makes the comet's tail. Every time a comet comes close to the Sun, a part of it melts. Over time, it will completely disappear. A comet does not give off any light of its own. Ice in the comet acts just like a mirror. What we see is sunlight bouncing off the comet. http://www.nasa.gov/audience/forkids/home/F_SC_comet.html

Comets Halebopp Comet http://www.nashttp://deepimpact.jpl.nasa.gov/science/comets.html

Looking through the center of the Milky Way http://www.nashttp://deepimpact.jpl.nasa.gov/science/comets.html

Questions and Discussion 1. Which characteristics are used to classify stars? A. temperature B. brightness (magnitude) C. mass D. All of the above

Questions and Discussion 1. Which characteristics are used to classify stars? A. temperature B. brightness (magnitude) C. mass D. All of the above

Questions and Discussion 1. Temperature and brightness are both used to classify stars as seen on the HR diagram, but mass is also important because it determines a stars temperature and brightness. http://hrw.com

Questions and Discussion 2. If a star becomes a black hole at the end of its life, it is a? A. high mass star B. nebula C. low mass star D. All of the above

Questions and Discussion 2. If a star becomes a black hole at the end of its life, it is a? A. high mass star B. nebula C. low mass star D. All of the above

Questions and Discussion 2. Becoming a black hole would mean that the star was a high mass star, giant actually as seen in the following illustration. http://www.enchantedlearning.com/subjects/astronomy/stars/lifecycle/

Questions and Discussion 3. Galaxies are classified based on their? A. composition B. color C. shape D. All of the above

Questions and Discussion 3. Galaxies are classified based on their? A. composition B. color C. shape D. All of the above

Questions and Discussion 3. Galaxies are classified based on their shape. This is evident because of their name categories. The categories of galaxies are spiral, elliptical and irregular. http://hrw.com

Questions and Discussion 4. Scientist believe that quasars give off as much light as 10 trillion suns because of their? A. composition B. distance and brightness C. shape D. color

Questions and Discussion 4. Scientist believe that quasars give off as much light as 10 trillion suns because of their? A. name B. distance and brightness C. shape D. color

Questions and Discussion 4. Scientist know the absolute brightness of a quasar known as PKS 0637-152, and they know that it gives off as much light as 10 trillion suns because of its calculated distance using parallax. http://hrw.com