BRAINCAKEBlack-Body Radiation
A black body is an idealised object that absorbs all the electromagnetic radiation that falls on it, at every wavelength. It is also the best possible emitter: when hot it emits a continuous spectrum of radiation called black-body radiation.
The shape of this spectrum depends only on the temperature of the body, not on what it is made of. Stars are a good approximation to black bodies, so their spectra can be used to find their surface temperatures.
The graph shows intensity (power emitted per unit wavelength) against wavelength for black bodies at three temperatures.
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
More in Space
- Stefan-Boltzmann Law
- Wien's Law
- Luminosity and Intensity
- The Inverse Square Law for Intensity
- Estimating Stellar Radius and Temperature
- The Hertzsprung-Russell Diagram
- Formation of a Star
- Life Cycle of a Star
All 18 lessons in Space · All Edexcel A-level Physics topics