Astronomy 1021 Lecture Notes - Lecture 10: 2M1207B, 2M1207, Brown Dwarf
12 Dec 2018
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Document Summary
Extrasolar planets: the new science of distant worlds. Star is a billion times brighter than a planet. When the planet is far from a star. When the star is relatively close to us. When the planet is relatively bright compared to its parent star. When you can mask the starlight without reducing the light from the planet. Most extrasolar planets have been discovered by indirect methods. Some systems have planets in orbital resonances with each other. Stars and planets orbit their centre of mass. Jupiter"s gravitational tug makes the sun wobble around the centre of mass. Suns motion is more complex due to gravitational tugs. Doppler technique used to measure changes in stars velocities. Can only detect velocities toward or away from us. You can see stars moving at a walking speed. Can determine orbital period, mass, and eccentricity. Gives us a precise determination of the period and orbital shape.
