Published online by Cambridge University Press: 08 February 2017
A historical review of integrated starlight, diffuse galactic light, and extragalactic light studies is presented. Together, these components compose the “background light.” Methods ranging from star counts to space-based photometric surveys have succeeded in quantifying the contribution of each component of the background. Integrated starlight is the dominant component. The contribution of diffuse galactic light in the general interstellar medium peaks slightly off the galactic plane and declines toward higher latitudes. The extragalactic light has been determined from both galaxy counts and photometric methods. The blue and red intensity and B–R color distribution of background light have been mapped. The relation between galactic structure and background light measurements is established. The distribution of interstellar extinction is the primary regulator of the brightness. However, spiral arm and stellar distribution effects are discerned in Carina and Sagittarius. The sun lies 13 pc north of the galactic plane as defined by brightness and dust distributions.