The Sinnerstad photometric system

Basic Reference

Sinnerstad U., Arkling J., Alm S.H., Brattlund P. 1968, Ark. Astr. 5, 105


The intensities of the absorption lines Hbeta, Hgamma and HeI 4471 have been determined by means of narrow-band technique. Although this technique is most important for measures of broad spectral features such as the hydrogen lines in early type stars, the accuracy of the photoelectrically determined HeI 4471 index is nevertheless comparable with the accuracy achieved in measurements of equivalent widths from high dispersion spectra. The Be stars are easily selected from a plot of Hbeta versus Hgamma. A photoelectric method is finally developed for the determination of the projected rotational velocity of the stars, V sini.


Access to the data and references

Asiago Database on Photometric System (ADPS)

Indices and Parameters

beta, gamma


  Filter  Wavelength   Width     Line
              [Å]       [Å]

    1        4340        20      Hgamma
    2        4340       165      Hgamma
    3        4861        20      Hbeta
    4        4861       164      Hbeta


EMI 6256 S
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Last update: 21 May 1996