NATS 1870 Study Guide - Midterm Guide: H-Alpha, Photosphere, Photon
19 Nov 2014
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Sc/nats 1870 understanding color - midterm review 02/06/2014. Black bodies: are objects which are heated to the point of glowing (produce a blackbody spectrum, objects which generate their own light. Stefan boltzmann law: hotter objects are brighter, emit more radiation, the amount of light emitted is proportional to the 4th power of the temperature, small change in temperature = brighter object. Wein"s law: the peak of the blackbody curve happens at longer wavelengths for cooler objects. O stars: blue in color, very hot (>20,000k) M stars: red in color, cooler (2000-3000k) This means the absorption lines will be much wider: in the a-type stars, hydrogen lines (hydrogen balmer lines) are the strongest. Hydrogen beta (2-4 energy level) 486nm: the surface gas temperature enables many electrons to be sitting in the second orbit (energy level) The balmer line transitions all connect to this level.
