AST101H5 Lecture Notes - Lecture 2: Angular Diameter, Full Moon, The Moons
Document Summary
Constellations are patterns of stars we see in the sky. Stars in the constellations may not be associated with each other in space, they may just appear grouped together as seen from earth. In ast101 we use the stars only as a fixed background to detect the movement of objects in the solar system. We see the sky that is above the horizon where we are standing. Using angles to identify things in the sky. How far apart in the sky objects look to us. The sun, moon and stars rise and set to us. The sun, moon, and stars themselves are not moving. 1 degree is a large angle in astronomy, which is about the size of the moon. 1 min. of arc (1") = 1 degrees divided by 60 still large units. Angular size depends on physical size and distance. The angle is a certain fraction of a complete circle.
