All stars radiate light over a broad range of frequencies in the electromagnetic spectrum from the low energy radio waves up to the highly energetic gamma rays. A star that emits predominately in the ultra-violet region of the spectrum produces a total amount of energy magnitudes larger than that produced in a star that emits principally in the infrared. Therefore, luminosity is a measure of energy emitted by a star over all wavelengths. The relationship between wavelength and energy was quantified by Einstein as E = h * v where v is the frequency, h is the Planck constant, and E is the photon energy in joules. That is, shorter wavelengths (and thus higher frequencies) correspond to higher energies
ALLMÄN KLASSIFICERING FÖR FÖRSKRIVNINGKDE40.1 KDE40.1