Flux Density Spectral Energy Density
Apparent Magnitude Ancient Greek Astronomers Visually determined brightness of stars Brightest - Magnitude 1 Faintest Star visible to the nnaked eye - Magnitude 6
Photmetric Magnitudes Filters Johnson UBV Bands Zero Point Set using Vega
Apparent Magnitude Zero point? Magnitude difference of 5
Absoulte Magnitude Intrinsic Property of the Source – Luminosity
K correction Distance Modulus
Bolometric Magnitudes Sometimes the band is sufficiently broad to allow the entire radiation from the source to pass through – particularly if it is dominated by a single line