ASTR 7,8,9,10

• Blackbody radiation:

  • energy carried by photons
  • increased temp = change in wavelengths
  • longer wavelengths - shorter wavelengths = red to yellow
  • brightness is proportional to increased amount of photons
• Temp for Blackbody Radiation:

  • 12000k is ultraviolet
  • 6000k is blue visible
  • 3000k is infrared
  • increased temp = shorter wavelenghts
• photons with shorter wavelengths have higher energy
• rutherford planetary model 1910

  • nucleus of protons and neutrons surrounded by electrons in orbit
  • mass of one proton or neutron is equal to ~ 2000 mass of electrons
• electron jumping of "n orbits"

  • going outwards n2 - n3 requires a photon of energy
  • going. inwards n2 - n1 requires emitting a photon
  • different atoms emit and absorb photons of differing specific wavelengths
  • cold photons release energy when they're heated
• spectroscope

  different elements have their own set of wavelengths

  when a chemical is burned, only certain wavelengths make up the light

  • emission spectrum of hydrogen spikes
  • comparing emission peaks identify chemicals
• clouds in space emit different coulors when rich in element

  oxygen = green

  hydrogen = red
• doppler effect

  in light, turns red (redshift) while object moving away and turns blue (blueshift) moving towards
• proper motion: a stars motion perpendicular to our line of sight across the celestial sphere
• radial velocity: motion along line of sight either toward or away, (proper motion but towards and away)
• the sun is made up of 3 layers: innermost -- outermost

  1. thermonuclear energy core: middle of sun, energy released by fusion of hydrogen into helium, helium into carbon, etc
  2. radiative zone: zone where energy is radiated into from the core
  3. convective zone: zone where energy is transferred by convection from radiative zone
• violent solar flares erupt from solar gases into space
• deepest layer of sun you can see is the photosphere
• photosphere: "light sphere" about 500km thick
• number of sunspots and solar flares periodicallly change, shortest cycle has been 11 years
• colorful layer is the chromosphere
• chromosphere: "color sphere" is ~ 2000 - 3000km thick
• sun's atmosphere is extremely dilute and hot, called the corona
• soure of sun's energy wasn't understoof till the 20th century

  • thermonuclear reactions, hydrogen fusion
  • 4H -> He + Y
  • E=mc^2