1. Stars and Galaxies Created by the Lunar and Planetary Institute For Educational Use Only Image at http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2009/07/image/g/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2009/07/image/g/results/50/

2. Welcome!  Please complete the pre-assessment  It’s for us—it’s not about you  Please let us know how much YOU know, not how much your friends sitting next to you know

3. What are we going to cover?  Our Place in the Universe  The Electromagnetic Spectrum  Classifying Stars  Classifying Galaxies  History of the Universe

4. First up…  Our Place in the Universe  What is our Universe made of?  How big are things? How far away?  How do we know?

5. What is our Universe made of?  Stars and planets  Gas and dust  Organized into star clusters  Organized into nebulae  Organized into galaxies  Other things:  Black holes  Dark matter  Dark energy What was in your drawing? Image from http://galileo.rice.edu/lib/student_work/astronomy95/orionpleiades.html http://galileo.rice.edu/lib/student_work/astronomy95/orionpleiades.html

6. Activity!!  Use the Venn diagrams to place the stickers—where does everything go?  After you’re finished, let’s discuss…

7. Examining the Components  Stars  Gas and dust (Nebulae)  Star clusters  Galaxies

8. Different types of stars Image from http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2003/21/image/a/results/50/ http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2003/21/image/a/results/50/

9. Types of Stars  Big  Small  Red  Blue  Yellow  In groups  Alone  More later

10. What is a “star cluster”?   stars formed together at same time   stars may be gravitationally bound together   two types: open (galactic) and globular Image at http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2007/18/image/a/format/web/results/50/ http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/2007/18/image/a/format/web/results/50/

11. Open Clusters   dozens to thousands of stars   young stars! only a few million years old   may still be surrounded by nebula from which they formed   located in the spiral arms of a galaxy   example: Pleiades Image at http://hubblesite.org/newscenter/archive/releases/star%20cluster/open/2004/20/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/star%20cluster/open/2004/20/image/a/results/50/

12. More open star clusters Image from http://hubblesite.org/newscenter/archive/releases/star%20cluster/open/2006/17/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/star%20cluster/open/2006/17/image/a/results/50/

13. Globular Clusters   millions to hundreds of millions of stars   old! 6 to 13 billion years   mostly red giants and dwarfs   stars are clumped closely together, especially near the center of the cluster (densely)   surround our disk as a halo Image at http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/1999/26/image/a/results/50/ http://hubblesite.org/newscenter/archive/releases/star%20cluster/globular/1999/26/image/a/results/50/

14. What is a “nebula”?  A cloud in space  Made of gas and dust   Can have stars inside  Most of the ones we see are inside our Milky Way Galaxy  Different types Orion image at http://hubblesite.org/newscenter/archive/releases/2006/01/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/2006/01/image/a/results/50/

15. Large, massive, bright nebulae Emission Nebula The hot gas is emitting lightThe hot gas is emitting light Orion image at http://hubblesite.org/newscenter/archive/releases/2006/01/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/2006/01/image/a/results/50/

16. Colder, darker nebulae Dark dust blocking the hot gas behind it NOAO/AURA/NSF Image from http://hubblesite.org/newscenter/archive/releases/nebula/dark/2001/12/image/c/results/50/ http://hubblesite.org/newscenter/archive/releases/nebula/dark/2001/12/image/c/results/50/

17. Leftovers from an Explosion Supernova remnant (smaller, less gas) Image at http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/

18. What is a “galaxy”?  A large group of stars outside of our own Milky Way  Made of billions to trillions of stars  Also may have gas and dust  Spiral, or elliptical, or irregular shaped Image at http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2007/41/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/spiral/2007/41/results/50/

19. Spiral galaxy--Andromeda NOAO/AURA/NSF Images at http://www.noao.edu/image_gallery/html/im0606.html and http://www.noao.edu/image_gallery/html/im0685.htmlhttp://www.noao.edu/image_gallery/html/im0606.html http://www.noao.edu/image_gallery/html/im0685.html

20. Elliptical Galaxies Images at http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2007/08/image/a/format/large_web/results/50/ and http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/1995/07/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/2007/08/image/a/format/large_web/results/50/http://hubblesite.org/newscenter/archive/releases/galaxy/elliptical/1995/07/results/50/

21. Irregular Galaxies NASA and NOAO/AURA/NSF Images at http://hubblesite.org/newscenter/archive/releases/galaxy/irregular/2005/09/results/50/, http://www.noao.edu/image_gallery/html/im0560.html, and http://www.noao.edu/image_gallery/html/im0993.html http://hubblesite.org/newscenter/archive/releases/galaxy/irregular/2005/09/results/50/ http://www.noao.edu/image_gallery/html/im0560.htmlhttp://www.noao.edu/image_gallery/html/im0993.html

22. Our Galaxy: the Milky Way   has about 200 billion stars, and lots of gas and dust   is a barred-spiral (we think)   about 100,000 light-years wide   our Sun is halfway to the edge, revolving at half a million miles per hour around the center of the Galaxy   takes our Solar System about 200 million years to revolve once around our galaxy

23. The Milky Way Image at http://news.nationalgeographic.com/news/bigphotos/1945371.htmlhttp://news.nationalgeographic.com/news/bigphotos/1945371.html

24. Mapping the Milky Way We can see stars  star clusters  nebulae  Galaxies  Let’s try to Map our Galaxy How do we know what our Galaxy looks like?

25. Measuring Distances  Parallax (let’s model it)   As Earth orbits the Sun, we see nearby stars move relative to more distant stars   How many degrees did the plate move, relative to the background?   Can you calculate the distance to the plate?   Sine of the parallax (angle) x Earth’s distance to the Sun = Distance to the star   The angles involved for strellar observations are very small and difficult to measure. Proxima Centauri, has a parallax of 0.77 arcsec. This angle is approximately the angle subtended by an object about 2 centimeters in diameter located about 5.3 kilometers away.

26. Measuring Distances  What is a Light Year?  A light year is the distance light travels in a year. Light moves at a velocity of about 300,000 kilometers (km) each second; how far would it move in a year?  About 10 trillion km (or about 6 trillion miles).  Why do we use light years?  Show me how far 5 centimeters is.  Now show me 50 centimeters.  Now tell me (without thinking about it, or calculating it in meters) how far 500 centemeters is. 2000? 20,000?  We need numbers that make sense to us in relationship to objects; we scale up and use meters and kilometers for large numbers.

27. Time for a Break! Next Up  Our Place in the Universe  The Electromagnetic Spectrum  Classifying Stars  Classifying Galaxies  History of the Universe

28. Let’s check your knowledge  Please draw an electromagnetic spectrum on a sheet of paper, and label the parts.  You can work in groups.

29. Radiation  There are lots of types of light (radiation), including visible and invisible Electromagnetic spectrum http://coolcosmos.ipac.caltech.edu/cosmic_classroom/ir_tutorial/what_is_ir.html.

30. Let’s Observe A Spectrum  What will the spectrum look like with a red filter in front of your eyes? A blue filter?  Hypothesize and test your hypothesis.  Now let’s examine the invisible parts— using our cell phones and a solar cell.

31.  There are different types of spectra  Continuous  Emission or Bright Line (from ionized gas, like a nebula or a neon sign)  Absorption or dark line (from stars) Illustration at http://imagine.gsfc.nasa.gov/docs/science/how_l1/spectra.htmlhttp://imagine.gsfc.nasa.gov/docs/science/how_l1/spectra.html

32. Radiation  All stars emit radiation  Radio, infrared, visible, ultraviolet, x-ray and even some gamma rays  Most sunlight is yellow-green visible light or close to it The Sun at X-ray wavelengths Image at http://imagine.gsfc.nasa.gov/docs/sc ience/know_l1/sun.html http://imagine.gsfc.nasa.gov/docs/sc ience/know_l1/sun.html Image and info at http://imagine.gsfc.nasa.gov/docs/teachers/gammaraybursts/imagine/page18.html http://imagine.gsfc.nasa.gov/docs/teachers/gammaraybursts/imagine/page18.html.

33. Using a Star’s Spectrum  We can use a star’s spectrum to classify it. NOAO/AURA/NSF image at http://antwrp.gsfc.nasa.gov/apod/ap010530.htmlhttp://antwrp.gsfc.nasa.gov/apod/ap010530.html

34. Stellar Evolution

35. Time to Create a Stellar Graph  Everyone will receive several “stars”  Place them on the large paper, according to their color and their brightness  This is a version of the Hertzsprung-Russell diagram.

36. Hertzsprung-Russell Diagram Images from http://www.nasa.gov/centers/goddard/news/topstory/2007/spectrum_plants.html and http://sunearthday.gsfc.nasa.gov/2009/TTT/65_surfacetemp.php http://www.nasa.gov/centers/goddard/news/topstory/2007/spectrum_plants.html http://sunearthday.gsfc.nasa.gov/2009/TTT/65_surfacetemp.php

37. Young stars form in nebulae from Small Magellanic Cloud Image at http://hubblesite.org/newscenter/archive/releases/2007/04/image/a/results/50/ http://hubblesite.org/newscenter/archive/releases/2007/04/image/a/results/50/

38. Star-forming region in the Large Magellanic Cloud: http://hubblesite.org/newscenter/archive/releases/2008/31/image/a/results/50/ http://hubblesite.org/newscenter/archive/releases/2008/31/image/a/results/50/

39. Orion image at http://hubblesite.org/newscenter/archive/releases/2006/01/image/a/results/50/http://hubblesite.org/newscenter/archive/releases/2006/01/image/a/results/50/

40. Interstellar “eggs” Movie at http://www.stsci.edu/EPA/PR/95/44/M16.mpghttp://www.stsci.edu/EPA/PR/95/44/M16.mpg

41. Our Sun is a Regular/ Small Star Image at http://www.gsfc.nasa.gov/topstory/20011210insidesun.htmlhttp://www.gsfc.nasa.gov/topstory/20011210insidesun.html On the “Main Sequence”

42. In a few Billion years… Red Giant Image at http://hubblesite.org/newscenter/archive/releases/1997/26/image/a/http://hubblesite.org/newscenter/archive/releases/1997/26/image/a/

43. Our Sun’s Habitable Zone Billions of years ago, things may have been different  The Sun was cooler (by up to 30%!)  Earth’s atmosphere was different (thicker, carbon dioxide)  Conditions will be different in the future  By many accounts, increases in the Sun’s temperature will make Earth uninhabitable in 1 billion years or less  These changes will also affect other planets… Mars? Animation at http://www.nasa. gov/97994main _BHabitableZon e.MPG http://www.nasa. gov/97994main _BHabitableZon e.MPG

44. By 5 billion years… White Dwarf Image at http://hubblesite.org/newscenter/archive/releases/nebula/planetary/1998/39/results/50/http://hubblesite.org/newscenter/archive/releases/nebula/planetary/1998/39/results/50/ Small, but very hot

45. Image at http://hubblesite.org/newscenter/archive/releases/nebula/planetary/2000/28/image/a/format/web_print/results/50/ http://hubblesite.org/newscenter/archive/releases/nebula/planetary/2000/28/image/a/format/web_print/results/50/