AST101H1 Lecture Notes - Lecture 25: Doppler Spectroscopy, Methods Of Detecting Exoplanets, Orbital Period

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Bryan Gaensler, C. Barth Netterfield, Ilana MacDonald

Document Summary

Spectra and atmosphere: still not that great, can"t be exactly sure. Doppler effect for light: sources moving toward you shift to higher frequency, blue shift, shorter wavelengths, sources moving away from you shift to lower frequency, red shift, shorter wavelengths. If a star is moving toward you it will appear bluer than normal. If a star is moving away from you it will appear redder than normal: very small change. If you look at the spectrum you can look at the wavelength of its absorption lines and compare to exact wavelengths. It will be slightly shifted to the red or the blue. The first extrasolar planet: 1995, around a star called 51 pegasi , no one actually saw the planet, radial velocity peaked at around 60 m/s, we can now measure motion of exoplanets at the speed of a snail. Inferred existence by the property of the star.