The ubvr photometric system

Basic Reference

Westerlund B.E. 1966, ApJ 145, 724


Thirty-five objects listed by Roberts as Wolf-Rayet stars have been observed photoelectrically in a narrow-band four-color system. The system is calibrated through observations of six spectrophotometric standard stars. Comparisons with the UBV system are presented. Criteria for separating single w-R stars from binaries as well as WC stars from WN stars are investigated. The distances of the W-R stars in Cygnus are discussed briefly.


Access to the data and references

Asiago Database on Photometric System (ADPS)

Indices and Parameters

v, v-r, b-v, u-b

Reddening-free parameters


Narrow-band interference filters from Baird Atomic

 Filter      wavelength   Width
                [Å]        [Å]

   r            5990        80
   y            5190       100
   b            4280        65
   u            3650       100


RCA 1P21

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Last update: 21 May 1996