[ASTRON 1010] - Final Exam Guide - Comprehensive Notes for the exam (46 pages long!)
Document Summary
Range from 10s of thousands of stars. Cloud is cool and dense, something cases gravitational contraction to start. The nebular theory of solar system formation illustrates the importance of rotation. Collisions between particles in the cloud cause it to flatten. A protostar looks star-like after the surrounding gas is blown away, but its thermal energy comes from gravitational contraction, no fusion. Contraction must continue until the core becomes hot enough for nuclear fusion: 10 million degrees kelvin. Contraction stops when the energy released by core fusion balances energy. Life tracks for different masses radiated from the surface- the star is now a main-sequence star. It take 30 million years for a star like the sun (less time for more massive stars, more time for less massive stars) Models show that sun required about 30 millions years. A life track illustrates a star"s surface temperature and luminosity. Photons exert a slight amount of pressure when they strike matter.
