AST101H1 Lecture Notes - Lecture 22: 30 Foot Fall, Doppler Spectroscopy, Exoplanet

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Bryan Gaensler

Document Summary

The doppler effect for light: sources moving towards you shift to higher frequency (shorter wavelengths, sources moving away from you shift to lower frequency (longer wavelength) Doppler only measures line of sight: object moving directly away, measure all of its speed, moving across our line of sight, measure none of its speed, moving diagonally, measure only part of its speed. In our perspective, the star wobbles toward and away from us. The first extrasolar planet: periodi(cid:272) doppler shifts of star (cid:862)51 pegasi(cid:863) i(cid:374)dire(cid:272)tl(cid:455) re(cid:448)ealed or(cid:271)iti(cid:374)g e(cid:454)opla(cid:374)et, 51. Pegasi b: radial velocity spiked at about 60m/s = 216kph, 1st extrasolar planet to be discovered around a sun like star (1995) Like 51 peg b have proven to most common type of exoplanet found in transit and doppler searches for exoplanets: completely at oods with nebular hypothesis. Hot jupiters & planetary migration: current notion: hot jupiters form in outer solar system, the(cid:374) (cid:373)o(cid:448)e i(cid:374)(cid:449)ard (cid:448)ia (cid:862)pla(cid:374)etar(cid:455) (cid:373)igratio(cid:374)(cid:863)