Semi-analytical formulas for the fundamental parameters of Galactic early B supergiants

The publication of new tables of calibration of some fundamental parameters of Galactic B0-B5 supergiants in the two classes $Ia$ and $Ib$ allow to particularize the eight parameters conjecture that model five fundamental parameters. The numerical expression for visual magnitude, radius, mass, luminosity and surface gravity are derived for supergiants in the range of temperature between 29700 and 15200. The presence of accurate tables of calibration allows us to introduce the efficiency of the derived formulas.