1. Constellations A natural human tendency is to see patterns and relationships between objects even when no true connection exists. Long ago, people connected the brightest stars into configurations called constellations, which ancient astronomers named after mythological beings, heroes, and animals—whatever was important to them. Does that cloud look like a “bunny” to you. OR What do you see in that ink blot?

2. Orion Some locations are better Stars are widely varied in color

3. Orion

4. Ursa Major

6. Ursa Minor

8. Scorpius

10. Cygnus

12. Sagittarius

14. Cross Cultures Astronomers of ancient China saw mythical figures different from those seen by the ancient Greeks, the Babylonians, and the people of other cultures, even though they were all looking at the same stars in the night sky. Interestingly, though, different cultures often made the same basic groupings of stars, despite widely varying interpretations of what they saw. For example, the group of seven stars usually known in North America as "the Dipper" is known as "the Wagon" or "the Plough" in Western Europe. The ancient Greeks regarded these same stars as the haunches and tail of "the Great Bear," while the Egyptians saw them as the leg of an ox.

15. Navigation Reasons to Group stars and create constellations: Entertainment Honor –Hero Hall of Fame –gods or leaders Keep track of where things are and the time –Calendars, Events Navigation

16. Patterns are Deceiving Constellations are NOT physically associated with each other, they just happen to be along your line of sight.

17. Our Moving Observatory Star trails Looking SouthEast Looking North

18. What’s Your Sign The Sun’s Position Determines your sign.

19. The Zodiac

20. Summer Constellations Looking South

21. Lyra and Cygnus Directly Overhead After Sunset in the summer and early fall.

22. Winter Constellations Looking South

23. Star Atlas Artistry Can You Find: Orion Taurus Canis Major Cancer Gemini

24. Hipparchus Most atlases of today have their origins with those that were derived from Hipparchus and used his “magnitude” system. 1st Rank Stars (The brightest stars in the sky) 6th Rank Stars (Barely visible with the unaided eye) Later, the magnitudes were rigorously defined so that a 5 magnitude difference = 100 x the intensity.

25. Magnitudes are more precise and changes in intensity are matched with apparent magnitudes. Vega = 0.0

26. Magnitude Scale Note:  M = 5 - 0 = 5  I = 100  1 = 100 or  M = 8 - 3 = 5  I = 1600  160 = 100

27. Brightness Scale I 1 /I 2 = 2.512 (m2-m1) I = intensitym v = apparent magnitude

28. Horizon based coordinate system –Horizon dependent (different for each observer) Altitude - Azimuth S W N E

29. Horizon based coordinate system –Horizon dependent (different for each observer) Azimuth Angle (degrees) –measured CW from N to E –N = 0 o, E = 90 o, S = 180 o, W = 270 o Altitude - Azimuth S W N E N 0 180 90E S 270W

30. Horizon based coordinate system –Horizon dependent (different for each observer) Azimuth Angle (degrees) –measured CW from N to E –N = 0 o, E = 90 o, S = 180 o, W = 270 o Altitude Angle(degrees) –horizon to star –Horizon = 0 o –Zenith = 90 o Altitude - Azimuth S W N E N 0 180 90E S 270W

31. “Bowl” Diagram Orienting yourself to a local horizon. N S W NCP Zenith Celestial Equator

32. Celestial Orientation

33. Right Ascension - Declination Geocentric Coordinates –Observer Independent Toward the Vernal Equinoxe (Position of the Sun on March 21-22 Celestial Equator (Earth’s Equator) North Celestial Pole (NCP)

34. Right Ascension - Declination Toward the Vernal Equinoxe = 0 hours Celestial Equator (Earth’s Equator) Right Ascension (hours) –Measured from the Vernal Equinoxe along the C.E. –Vernal Eq. = 0 hours RA

35. Right Ascension - Declination Toward the Vernal Equinoxe = 0 hours Celestial Equator (Earth’s Equator) Declination (degrees) –Measured from the Celestial Equator to the Pole –CE = 0 o –NCP = 90 o NCP DEC

36. Sky Atlas Right Ascension Declination Magnitude

37. Sky Atlas Constellation Lyra, Bright Star Vega