1. Astronomy is a nocturnal activity 1953, T. E. Houck and A. D. Code

2. The sky above us

3. Stars dominate the night sky Relative positions of stars remains fixed The whole pattern revolves around us Constellations – patterns in star distribution Constellations vary – related to mythology Constellations not real 1929 IUA – 88 official constellations Every star belongs to a constellation

4. Orion Constellation

5. Map of Orion Constellation

6. The wanderers Sun, Moon, planets move relative to stars Wander in a narrow band – Zodiac Ecliptic

7. The Zodiac

8. The Ecliptic

9. The Celestial Sphere 23.5 

10. Earth’s prograde rotation

11. Ursa Minor

12. Precession of Earth’s spin 26,000 years period

13. Equatorial Coordinates

14. Examples Orion: Right Ascension: 5 hours Declination: 5 degrees Ursa Major = Saptarshi Mandal The Great Bear (Big Dipper) Right Ascension: 11 hours Declination: 50 degrees

15. Image Sources

16. http://fourmilab.ch/yoursky/

17. Image Sources