PPT Slide
Fundamental Astronomy: Brightnesses
Stellar Flux And Luminosity
At visual wavelengths, the Sun has a luminosity:
Note I say at visual wavelengths because the flux we usually measure is in the visual part of the electromagnetic spectrum.
To measure the true total luminosity, one must measure the flux at all wavelengths (not so easy!)
The total luminosity measured over all wavelengths is called the bolometric luminosity