A W UMa variable in the visual binary system ADS 9019 - A UBV photoelectric investigation UBV and light curve data on the binary system ADS 9019 are reported andthe geometry of the pair is discussed. The 1950.0 coordinates,magnitudes, colors and HD spectral types for the binary, a comparisonand a check star are furnished, along with 402 UBV observations of thenonvarying ADS 9019 primary. Orbital elements were employed to generatetheoretical light curves. The data indicate an almost identical pair,one being slightly smaller and cooler than the other. The constant lightvariation with strongly inflected maxima and minima of equal depthcategorizes the object as a W UMa contact binary.