1 / 37

Constellations

Constellations. A natural human tendency is to see patterns and relationships between objects even when no true connection exists.

hume
Download Presentation

Constellations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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

  5. Ursa Major

  6. Ursa Minor

  7. Ursa Minor

  8. Scorpius

  9. Scorpius

  10. Cygnus

  11. Cygnus

  12. Sagittarius

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

  26. Magnitude Scale Note: DM = 5 - 0 = 5 DI = 100 1 = 100 or DM = 8 - 3 = 5 DI = 1600  160 = 100

  27. Brightness Scale I1/I2 = 2.512(m2-m1) I = intensity mv = apparent magnitude

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

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

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

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

  32. Celestial Orientation

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

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

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

  36. Sky Atlas Declination Right Ascension Magnitude

  37. Sky Atlas Constellation Lyra, Bright Star Vega

More Related