Astronomy is a nocturnal activity 1953, T. E. Houck and A. D. Code
The sky above us
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
Orion Constellation
Map of Orion Constellation
The wanderers Sun, Moon, planets move relative to stars Wander in a narrow band – Zodiac Ecliptic
The Zodiac
The Ecliptic
The Celestial Sphere 23.5
Earth’s prograde rotation
Ursa Minor
Precession of Earth’s spin 26,000 years period
Equatorial Coordinates
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
Image Sources
Image Sources http://fourmilab.ch/yoursky/
Image Sources