9 24.1 The Study of LightVisible light from sun is only a small part of what’s emittedElectromagnetic wavesRadio waves, IR, light, UV, X-raysWavelength is the differenceROYGBIV186,000 miles/hr…all waves
12 Light Comes in “packets” called photons Is both a waves and a particle Radiation pressure is the “push” of the particle of lightSpectroscopy = the study of light’s properties
13 SpectraContinuous spectrumA continuous band of color
14 Spectra2. Absorption spectrumDark lines running through it
15 Spectra 3. Emission spectrum Bright lines emitted A star’s spectra = its fingerprint…tells what elements are in the star.
16 Doppler EffectThe change in frequency, either higher or lower, when wave source is moving.The pith gets higher or lower for sound.Applies to any waveHigher (blue shift) – moving to usLower (red shift) – moving away
39 24.3 The Sun Just 1 of 10,000,000,000 stars in Milky Way Joe average starOnly close star for study109 earths wide1.25 million earth’s volume
40 Sun Facts IT’S A GAS…it doesn’t have a solid surface! 4 parts Interior PhotosphereChromosphereCorona
41 Interior Nuclear fusion provides energy 4 hydrogen make 1 helium & energyMass is lost in reaction… E = mc2!4 million tons of hydrogen are lost each second …Can still last for 10 billion yrs!Internal temp = 15 million degrees!
42 Photosphere A 300 mile thick surface covering Looks grainy on surface From rising/sinking hot gasConvection currents90% hydrogen, 10% Helium (sun)6000 degrees
44 Corona Another thin layer of hot gases Extends 600,000 miles out Hot gas “blows” out from sun = solar winds, at 500 miles/secCauses the Northern Lights1,000,000 degrees
45 The Active Sun Spins on axis like planets 25 days at eq, 33 days near top/botSunspots = dark regionsOn an 11 year cycleProminences – ejected materialSolar flares – bright sunspots that eject material and high energyAurora Borealis – form solar flares