Effective temperature

The effective temperature of a star is the temperature, which should have a black body to shine with the same brightness per area.

Valid according to the Stefan- Boltzmann law

It is

The Stefan- Boltzmann constant. Thus, the bolometric magnitude to results

Where the stellar radius is. Since the stellar radius is not to be clearly defined, one uses to calculate the effective temperature, the optical density. The effective temperature and the bolometric magnitude are the two important physical parameters with which a star can be placed in the Hertzsprung -Russell diagram. The effective temperature of our sun is about 5780 K. The effective temperature of an object differs from the temperature kinetically defined all the more from the less the spectrum of the object corresponds to a black body.