The effective temperature of a celestial body is a measure of its radiation output as if it were a perfect blackbody. In other words, it is the temperature at which an object would emit radiation equal in intensity to that of the object's actual emissions. Other synonyms for effective temperature include blackbody temperature, radiative equilibrium temperature, and equilibrium temperature. The effective temperature is an important parameter in astrophysics and is used to study the physical properties of stars, planets, and other celestial objects. It is also used in engineering to design systems that operate at high temperatures, such as jet engines and nuclear reactors.