Observing Night #1 Dr. Henry Throop / University of Colorado 13-Jun-2000 Things to notice: Stars twinkle -- like hot parking lot effect, or lines on bottom of swimming pool Light pollution -- from Denver, Boulder How many stars are there total? Colors of Stars Red, Blue, White Brightness of Stars Related to distance _or_ intrinsic brightness Constellations Summer triangle Lyra (lyre): Vega Cygnus (swan): Deneb Aquila (eagle): Altair Delphinus Big Dipper (ie, Ursa Major = big bear) Little Dipper (ie, Ursa Minor = little bear) Casspiopeia Sagittarius Bootes & Arcturus Scorpio Objects Milky Way Polaris Ring nebula M57 in Lyra Double double in big dip Double Cluster Globular clusters (10^5-6 stars, old, symmetric) Open clusters (10^2-3 stars, more random-looking) Andromedea Galaxy Concepts & definitions Meridian -- line from polaris to zenith to n/s horizons North Celestial Pole Ecliptic Zenith Moon Synchronous rotation -- always seeing same side Craters Lava fields (maria, mare, seas, sea of tranquility, etc. -- darker, fresher, newer, smoother) It's dark! Crater shadows Ejecta from big craters Light from moon -- can't see stars nearby because of glare