The Strömgren photometric system, abbreviated also as uvbyβ or simply uvby, and sometimes referred as Strömgren - Crawford photometric system, is a four-colour medium-passband photometric system plus Hβ (H-beta) filters for determining magnitudes and obtaining spectral classification of stars.
Its use was pioneered by the Danish astronomer Bengt Strömgren in 1956[1] and was extended by his colleague the American astronomer David L. Crawford in 1958.
[2] It is often considered to be a powerful tool and successful investigating the brightness and effective temperature of stars.
This photometric system also has a general advantage as it can be used to measure the effects of reddening and interstellar extinction.
[3] This system also allows calculation of parameters from the
without the effects of reddening, termed
[3] The following table shows the characteristics of each of the filters used (represented colors are only approximate): There are four main highly applied and technical indices: