Refractor and Reflector

1. RECAP Mirror Lens Refractor and Reflector

2. The Celestial Sphere & more on Constellations(Week 4)

3. 90 deg. 34 deg. Latitude Rotation Daily Changes Revolution Monthly Changes Why do we see what we see??

4. The Zodiac

5. Constellations – the 88 semi-rectangular regions that make up the sky • Northern constellations have Latinized Greek-mythology names: • Orion, Cygnus, Leo, Ursa Major, Canis Major, Canis Minor • Southern constellations have Latin names: • Telescopium, Sextans, Pyxis

9. What do you think? • What causes the stars to move? • Do the stars actually move in the way they appear from Earth? • Do the stars stay in the same position in the sky all day/night long?

10. Consider the dome of the sky over our heads…. mixing bowl

11. Consider the dome of the sky over our heads…. inverted mixing bowl ….

12. Imagining a spinning Celestial Sphere surrounding Earth aids in thinking about the position and motion of the sky Animation of Celestial Sphere http://bcs.whfreeman.com/universe6e/pages/bcs-main.asp?v=category&s=00110&n=01000&i=02110.02&o=|02000|01000|&ns=0

13. Imagining a spinning Celestial Sphere surrounding Earth aids in thinking about the position and motion of the sky

14. Altitude is like latitude or declination

15. Celestial Sphere Rotation Celestial Sphere Rotation Star B Star B 2 2 Star A Star A 1 2 2 1 North Star Celestial Sphere Celestial Sphere 3 3 1 1 4 4 3 3 Horizon Earth’s Equator 4 4 Celestial Sphere Rotation Celestial Sphere Rotation Figure 1 Figure 2 1) Explain how to find North on the horizon from the North star. 2) Where is the North star when you’re at the North pole?

16. Celestial Sphere Rotation Star B 2 Star A 1 2 Celestial Sphere Celestial Sphere 3 1 4 3 Horizon 4 Celestial Sphere Rotation Figure 2 1) Is the horizon shown a real physical horizon, or an imaginary plane that extends from the observer and Earth out to the stars? 2) Can the observer shown see an object located below the horizon? 3) Is there a star that is in an unobservable position? 4)When a star travels from being below the observer’s horizon to being above the observer’s horizon, is that star rising or setting?

17. Tutorial: Position – p.1 PUT NAMES in Tutorials • Work with a partner • Read the instructions and questions carefully • Talk to each other and discuss your answers with each another • Come to a consensus answer you both agree on • If you get stuck or are not sure of your answer ask another group • If you get really stuck or don’t understand what the Lecture Tutorial is asking ask your Professor for help • I WILL BEGIN STAMPING TUTORIALS A LITTLE BEFORE YOU FINISH THE TUTORIAL SINCE THERE ARE 70+ OF YOU, BUT YOU MUST ALL FINISH THE TUTORIAL OR YOU WILL GET A ZERO! DO NOT WALK OUT OF THE ROOM OR GET OFF TASK WHEN WE ARE COMPLETING A TUTORIAL OR YOU WILL GET POINTS DEDUCTED OR GET A ZERO! • IF THE TUTORIAL IS COMPLETED AT THE END OF LECTURE, NO ONE IS ALLOWED TO LEAVE EARLY UNLESS YOU CHECK WITH ME FIRST! IF YOU LEAVE EARLY YOU’LL GET A ZERO.

18. Did you get the Key Ideas from the Position Lecture Tutorial?

19. Celestial Sphere Rotation Star B 2 Star A 1 2 Celestial Sphere Celestial Sphere 3 1 4 3 Horizon 4 Celestial Sphere Rotation Figure 2 In what direction is the observer facing? • toward the South • toward the North • toward the East • toward the West

20. Celestial Sphere Rotation Star B 2 Star A 1 2 Celestial Sphere Celestial Sphere 3 1 4 3 Horizon 4 Celestial Sphere Rotation Figure 2 Imagine that from your current location you observe a star rising directly in the east. When this star reaches its highest position above the horizon, where will it be? • high in the northern sky • high in the southern sky • high in the western sky • directly overhead

21. Celestial Sphere Rotation Star B 2 Star A 1 2 Celestial Sphere Celestial Sphere 3 1 4 3 Horizon 4 Celestial Sphere Rotation Figure 2 Where would the observer look to see the star indicated by the arrow? • High in the Northeast • High in the Southeast • High in the Northwest • High in the Southwest

23. Telescope Field of View Moon=0.5 deg. Field of View = Eyepiece apparent FOV ÷ Magnification Large Magnification = Small field of view Small Magnification = Large Field of view

28. Right Ascension (RA) and Declination (Dec) are similar to latitude and longitude on the surface of the Earth. Latitude and longitude are fixed with respect to positions on Earth. But RA and Dec are fixed with respect to positions of stars in the sky. What is moving, the celestial sphere or the Earth? To an Earthling observer, what appears to move? Declination (like latitude) is measured in degrees north or south of the Celestial equator. Right ascension (like longitude) is measured in units of hours, minutes, and seconds eastward from the position of the vernal equinox on the Celestial equator. The Vernal Equinox is the position of the Sun on the first day of Spring.