I am taking astrophysics course and we are constantly talking about Luminosity,Brightness,Intensity,Flux etc. I thought that I understand the idea properly but I see now that I dont.
Intensity is the light passing through a steradian per second
Luminosity is intensity per area
And Flux is the Luminosity per area ?
$$F= L/4\pi r^2$$
And brightness = Flux
Are these statements true ?
I am confusing these definitions and their meanings constantly. Can someone help me to understand it better.