AS101 Chapter Notes - Chapter 1: Farthest North, Photosphere, Lunar Phase
Document Summary
Field of view: the area visible in an image. Usually given as the diameter of the region. Solar system: the sun and its planets, asteroids, comets and so on. Planet: a non-luminous body in orbit around a star, large enough to be spherical and to have cleared its orbital zone of other objects. Star: a globe of gas held together by its own gravity and supported by the internal pressure of its hot gases, which generate energy by nuclear fusion. Astronomical unit (au): average distance from earth to the sun; 1. 5 x 108 km, or 93. 3 miles. Light year: unit of distance equal to the distance light travels in one year. Starlight is recorded by brigtness and this is how they are displayed in astronomical diagrams. The size of a star image in a photograph tells you not how big the star really is but only how bright it looks.
