UBV system

UBV system

[¦yü‚bē¦vē ‚sis·təm]
(astronomy)
A system of stellar magnitudes in which an object's apparent magnitude is measured at three wavelengths, labeled U, at 360 nanometers; B, at 420 nanometers; and V, at 540 nanometers; and is characterized by the color indices B-V and U-B, which are both defined to be 0 for a star of spectral type A0. Also known as Johnson-Morgan system.
References in periodicals archive ?
Mermilliod JC: Photoelectric Photometric Catalogue of Homogenous Measurements in the UBV system.
Photometry measured on the Johnson UBV system on the nights of 12, 25 and 26 July 1978 with the 0.