AST101H5 Chapter Notes - Chapter 10: 51 Pegasi, Orbital Speed, Blueshift
Document Summary
If the nebular theory is correct, then every start should have planets. Called extrasolar planets or exoplanets because they are exterior to our solar system. Challenge: exoplanets are extremely small and don"t reflect that much light. Because a star is so much brighter than its planets. Must block out the star"s light to see the much fainter planets next to the star. Must prove any detection is really a planet: planets orbit around the star over time, planets move with the star through space. We conclude there is a planet from an observation of the start it is orbiting. Type types of observations: observe the motion of the start to detect it has planets, observe the brightness of the star to detect it has planets. These provide different types of information so it"s good to use both and combine them. A planet does not orbit around its star.
