Black Body Radiation

The key to understanding the light from stars, even the Sun, starts with astronomers' ability to measure radiation at different wavelengths and different temperatures. A black body curve shows the intensity of radiation of different frequencies emitted by an object. Wien’s law tells astronomers that the wavelength an object radiates and is inversely proportional to its temperature. Stefan-Boltzmann’s law tells astronomers that the total amount of energy is proportional to the fourth power of the temperature. It was proven that Wien’s formula worked best for the shorter wavelengths and higher frequencies. Max Planck found that electromagnetic energy is emitted in discrete units or “quanta.” He also found that an intensity wavelength graph can be used to find the temperature of an object emitting electromagnetic radiation. The higher the frequency and shorter the wavelength, the greater the energy.