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. Image Sources

17. Image Sources