The document discusses the celestial sphere, which is used as a model to visualize objects in the night sky. It describes key features of the celestial sphere including the celestial equator, poles, ecliptic, and constellations. It also discusses celestial coordinates such as declination and right ascension that are used to locate celestial objects, and how the apparent motions of the Earth result in phenomena like seasons and precession.

1. Understanding the Starry Sky Ch. 01

3. Celestial Sphere http://www.astro.columbia.edu/~archung/labs/fall2001/lec02_fall01.html

6. Ecliptic & Celestial Sphere http://www.utm.utoronto.ca/services/gallery/img/ecliptic.gif

8. In order to more easily locate objects in the sky, we divide the sky into regions named after familiar patterns of stars called constellations . Ancient constellations were imaginary pictures outlined by familiar patterns of stars (stick figures). Modern astronomers divide the sky into 88 official constellations or regions of space, many of which contain the ancient star patterns.

9. Sphere image of Constellation Boundaries

12. Circumpolar Stars http://www.nmm.ac.uk/upload/img/circumpolar.jpg

13. “ Star Trails”

14. N & S Circumpolar Stars http://www.mhhe.com/physsci/astronomy/fix/student/images/01f19.jpg

16. Horizon Star Map http://www.drypen.net/Star_Map_3.jpg

17. Equatorial Star map http://www.starlight-theatre.ca/images/MAP-C.GIF

20. Apparent Magnitude Scale

21. Terrestrial Coordinates http://www2.shastacollege.edu/dscollon/images/Figures,%20Diagrams%20and%20Maps.htm

23. Celestial Globe http://www.onr.navy.mil/focus/spacesciences/observingsky/sphere1.htm

24. RA & Dec http://abyss.uoregon.edu/~js/ast122/lectures/lec02.html

25. Summary Earth Globe Celestial Sphere North Pole North Celestial Pole South Pole South Celestial Pole Equator Celestial Equator Prime Meridian Vernal Equinox Latitude Declination Longitude Right Ascension

27. Horizon System Diagram http://www.yorku.ca/phall/P1070W05/L04/bea02-05.jpg

28. Altitude & Azimuth http://www.nmm.ac.uk/upload/img/altaz-star2.jpg

30. Angular Measure http://www.physics.capcollege.bc.ca/stan/Angular_measure.jpg

32. Geometric Explanation p = Location x ° = Latitude a° = Altitude of Polaris x° = a° http://homepage.mac.com/kvmagruder/images/polarislat.gif

34. Earth’s Motions: Rotation, Revolution

35. Revolution

37. Seasonal Heights of Sun

38. Seasonal Sun Paths http://www.madison.k12.wi.us/planetarium/sunpath.gif

39. Seasonal Constellations SEPTEMBER MARCH

40. Earth’s Seasons http://www.learn.londonmet.ac.uk/packages/clear/visual/daylight/sun_sky/images/seasons.png

41. Earth’s Seasons

43. Seasons & Celestial Sphere

44. Rotation: Solar and Sidereal Day http://www.nmm.ac.uk/upload/img/sidereal-mean-day_20030415143827.gif

45. Sidereal Day  

47. Precession http://earthobservatory.nasa.gov/Library/Giants/Milankovitch/milankovitch_2a_low.html

48. Earth’s Precession http://apollo.lsc.vsc.edu/classes/met130/notes/chapter18/graphics/precession.psd.gif

49. Inconstant North Star 14,000 AD Present + North Ecliptic Pole + Ancient Egyptian polestar “ But I am as constant as the North Star…” -Shakespeare, Julius Caesar

50. http://abyss.uoregon.edu/~js/images/bz990323.gif