Jansky

Unit of spectral flux density

The jansky (symbol Jy, plural janskys) is a non-SI unit of spectral flux density, or spectral irradiance, used especially in radio astronomy. It is equivalent to 10−26 watts per square metre per hertz. The spectral flux density or monochromatic flux, S, of a source is the integral of the spectral radiance, B, over the source solid angle: S = ∬ source B ( θ , ϕ) d Ω .

From Wikipedia, under CC BY-SA. More on occurri.