apparent magnitude

Apparent magnitude is a magnitude-style (logarithmic) measurement of brightness indicating the brightness as seen from Earth, adjusted only to cancel the effects of Earth atmosphere. The commonly used apparent magnitude is calibrated to indicate the ratio of the object's apparent brightness with that of the star, Vega, i.e., with 0 taken as Vega's apparent magnitude (Vega system). Some such apparent magnitudes:

• -26.74 - Sun.
• -12.92 - Moon, maximum.
• -4.89 - Venus, maximum.
• -1.47 - Sirius.
• -0.01 - Alpha Centauri A.

The unmodified term magnitude likely most often means apparent magnitude. Magnitudes cited for observations through filters are generally apparent magnitudes. Cited apparent magnitudes can refer to the visible light magnitude (generally that through the V filter), or alternately, a bolometric magnitude (sometimes cited as the apparent bolometric magnitude). These can differ substantially and for precision, you need to note which.