  Based on the maximum entropy production principle, a relation between
luminosity and effective temperature for main-sequence stars is obtained.
Simplicity of the derivation and absence of any empirical parameters in the
result is a fundamental difference of the present method from the classic ones
where equations of stellar structure are analyzed. Using available photometric
data (Webda, GCG) for more than 7.5 thousand stars, it is shown that the
obtained luminosity-temperature relation is better than previously used ones.
