AS101 Lecture Notes - Lecture 3: Ptolemy, Aldebaran, Angular Diameter
Document Summary
Lecture 3: milky way: a band of light making a circle around the celestial sphere. Constellations: ancient civilizations around the world named groups of stars called constellations, based on ancient heroes, gods, animals and mythologies, many star patterns recognized today originated 5000 years with the. Star names: may actually be quite far away from each other. The brightest stars in a constellation : sirius- greek glowing , aldeberan- arabic follower , vega- arabic landing , spica- latin the ear of wheat of virgo . Brightest stars usually alpha and second brightest beta etc . Angular size and distance: full circle = 360 o, 1 o=60 (arciminutes, ecliptic is sun"s apparent path through the celestial sphere, 1" =60" (arcseconds) The angular size of your finger at arm"s length is about 1 o. How many arcseconds is: an object"s angular size appears smaller if it is farther away.