Photometry (astronomy)
the determination of light intensities of astronomical bodies, including stars
Photometry is a method of problem solving in astronomy. It aims to measure flux. When photometry is performed over broad wavelength bands of radiation, where not only the amount of radiation but also its spectral distribution is measured, the term spectrophotometry is used.
The word is combination of the Greek affixes "photo-" ("light") and "-metry" ("measure").