Astronomy 1021 Chapter Notes - Chapter 11: Aurora, Chromosphere, Photosphere

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Chris Racknor

Document Summary

Its total power output, called luminosity, is about 3. 8 x 1026 watts o. 1 second of the sun"s luminosity can meet our energy demands for 500,000 years. Gravitational contraction- the collapse of gas and dust to form stars, planets and other objects, under gravitational attraction. The process leads to the release of potential energy as the mass becomes more closely packed. Energy has a lot of mass, and the formula explains that the sun"s mass is enough to product large amounts of energy for billions of years. Nuclear fusion is how the sun is powered o. 4 hydrogen atoms joining together for form 1 helium atom through quantum mechanics. *note: nuclear power plants use nuclear fission, not fusion. Strong force- binds neutrons and protons together in an atomic nucleus, but only act on very short distances o. This is the force that allows for hydrogen fusion in the sun which provides its energy.