17-21-097

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 (Epb/Eo)
where Epb is the point brilliance of the star considered, mo and Eo are constants based on the magnitudes ascribed to certain standard stars

Note 1 to entry: In addition to the (visual) apparent magnitude defined here, other apparent magnitudes (photographic, bolometric, etc.) are defined by the same formula, but where Epb and Eo are the responses of a detector having a specified spectral responsivity.

Note 2 to entry: The apparent magnitude has unit one.

Note 3 to entry: This entry was numbered 845-01-60 in IEC 60050-845:1987.

Note 4 to entry: This entry was numbered 17-50 in CIE S 017:2011.

Publication date: 2020-12