Astronomy 1021 Lecture Notes - Lecture 10: Planetary Migration, Exoplanet, Gravitational Lens

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

Document Summary

Astronomy chapter 10: other planetary systems, the new science of distant worlds. Extrasolar planets are planets that orbit stars that lie beyond our own solar system. Presents a challenge in 2 ways: planets are small compared to the distances between stars, starlight overwhelms any planet in a photo. We can learn about a distant object in 2 ways: directly: pictures, indirectly: inferring an objects existence or properies without actually seeing it. All objects in a star system orbit the systems balance point , or centre of mass. Planets exert gravitaional tugs on their star, causing the star to orbit around the system"s centre of mass. Astronomer use 2 two disinct observaion methods to search for gravitaional tugs of planets on stars. One is astrometric method, which uses very precise measurements of stellar posiions in the sky to look for the slight moion caused by orbiing planets (wobbles)