EASC 108 Lecture Notes - Lecture 17: Accretion Disk, Debris Disk, Planetary Migration

• School: Simon Fraser University
• Department: Earth Sciences
• Course: EASC 108
• Professor: Glyn Williams- Jones

Document Summary

Create central gap at stars co-rotation distance. Open gap in disk slowly migrates inward. Planets can migrate further by scattering small bodies. Sun-like star is ~billion times brighter than light reflected from its planets. Equivalent to being in vancouver and trying to see a pinhead 15 meters from a grapefruit in montreal. In 1991, first planets discovered since pluto, found orbiting a pulsar, a rapidly rotating neutron star. Remains of giant stars that became supernovas regular periods so best time keeps in the universe! Pulsars send out 2 beams of radio energy as they rotate, e. g. lighthouse. Psr b1257+12 showed regular deviations in its pulsing! Gravitational pull of objects orbiting pulsar causes the pulsar to wobble and make the pulses arrive first late and then early. Finding planetary systems: astrometric method gravitational tugs! Sun and jupiter orbit around common centre of mass. Sun thus wobbles around that centre of mass with same period as jupiter.