Lecture 13: Understanding Light and Its Interactions with Substances - Prof. Robert E. Erg, Study notes of Astronomy

Download Lecture 13: Understanding Light and Its Interactions with Substances - Prof. Robert E. Erg and more Study notes Astronomy in PDF only on Docsity! ASTR1030 - FALL, 2008, LECTURE 13; PAGE 1 ASTR1030 Announcements http://lasp.colorado.edu/~ergun/ ASTR1030/ Wednesday, October 8: Lecture by Seth Jabcobson. • This weeks reading: Chapter 6. Today • Light ASTR1030 - FALL, 2008, LECTURE 13; PAGE 2 Light Spectrum Radio Waves Infrared Radiation Visible Light Ultraviolet Radiation X-Rays Gamma Rays ASTR1030 - FALL, 2008, LECTURE 13; PAGE 5 Light: Emission ASTR1030 - FALL, 2008, LECTURE 13; PAGE 6 Light: Emission Every substance has a distinct emission pattern or finger print. Important Point: We can tell what a planet or star is made of by analyzing the emission spectrum. Magnified View ASTR1030 - FALL, 2008, LECTURE 13; PAGE 7 Light: Absorption/Transmission Every substance has a distinct absorption pattern or finger print. Important Point: We can tell what a gas is made of by analyzing the absorption spectrum. Magnified View tar Cloud ASTR1030 - FALL, 2008, LECTURE 13; PAGE 10 Light Doppler Shift Example: The 557.7 nm O+ green line is from a comet is seen at 557.8 nm. Is Jupiter moving toward or away from us? How fast in km/s? A: Away. The wavelength is longer, so the light is red-shifted. v c -- λshift λlaboratory– λlaboratory ------------------------------------------= v c ∆λ λ0 ------= v c ∆λ λ0 ------ 3 10 8 m s⁄×( ) 0.1nm 557.7nm -------------------- 5.4x10 4m s --- 54 km s ------= = = = ASTR1030 - FALL, 2008. LECTURE 13; PAGE 11 Visible Light 400 nm 700 nm550 nm Your eye cannot distinguish pure yellow (477 nm) from a mixture of red and green. ASTR1030 - FALL, 2008. LECTURE 13; PAGE 12 Visible Light 110 100 an Er ane ASTR1030 - FALL, 2008. LECTURE 13; PAGE 15  rear tes a allabe NASA/IPAC ASTR1030 - FALL, 2008. LECTURE 13; PAGE 16  rater ales rote et ead ASTR1030 - FALL, 2008. LECTURE 13; PAGE 17 ASTR1030 - FALL, 2008. LECTURE 13; PAGE 20 Multi-Spectral Astronomy: CasA Radio IR Visible UV X-Ray ASTR1030 - FALL, 2008. LECTURE 13; PAGE 21 Multi-Spectral Astronomy: Venus Radio IR Visible UV X-Ray ASTR1030 - FALL, 2008. LECTURE 13; PAGE 22 Multi-Spectral Astronomy: Venus Radio IR Visible UV X-Ray