apparent magnitude (of an astronomical object) [m]
quantity that correlates with the more or less luminous aspect of a star and that is defined by the formula
m = mo - 2,5 log10 (E/Eo)
where E is the point brilliance of the star considered, mo and Eo are constants based on the magnitudes ascribed to certain standard stars
NOTE In addition to the visual apparent magnitude defined here, other apparent magnitudes (photographic, bolometric, etc.) are defined by the same formula, but where E and Eo are the responses of a detector having a specified spectral responsivity.