Across 1. A stellar behavior which broadens lines, adding both red- and blueshift to the wavengths coming from the star 4. An effect which slightly shifts the wavength of a moving source 6. Highest energy photon 9. Constant, even in different moving frames of reference 12. Description of all the radiation from an object 15. The _____________ needed for line radiation can come from collisions in a hot gas, collisions with a fast stream of particles, or UV radiation. 16. A stellar effect which causes a periodic shift in the calculated velocity. 18. Radiation characteristic of the sun 19. invisible to the eye. detected by skin

Down 1. Perceived color of a cool, infrared star 2. Ionizing radiation, useful with caution 3. We can't resolve a virus with visible light because the _________________ of such light is longer than a virus. 5. Very narrow intervals of wavelength, with wavelengths characteristic of particular elements 7. Perfect radiator & absorber 8. Radiation from an opaque surface depends only on the _____________________ 10. Analysis of a line spectrum must yield both temperature and _____________________ 11. Some wavelengths in this range are absorbed and radiated by water 13. A bit of radiant energy 14. Passes through air, absorbed by ozone 17. Long wavelengths usually described by frequency