Aparent Visual Magnitude -
"Visual magnitude" is a scale used by astronomers to measure the brightness
of a star. The term "visual" means the brightness is being measured in the
visible part of the spectrum,
the part you can see with your eye (usually around 5500 angstroms).
Astronomers usually refer to "apparent magnitudes", that is, how bright
a star appears to us here at Earth. Apparent magnitudes are often written
with a lower case "m".
For more on magnitude see http://liftoff.msfc.nasa.gov/academy/universe/mag.html