Strömgren photometric system

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Strömgren photometric system (uvby) (sometimes also referred as Strömgren - Crawford photometric system) is four-colour medium-band photometric system (plus H-beta filter) for stellar classification. It was pioneered by the Danish astronomer Bengt Strömgren in 1956 and extended by his colleague the American astronomer David L. Crawford in 1958.

Contents

[edit] Indices and parameters

V, b-y, m1, c1, beta

m1 = (v - b) - (b - y)

c1 = (u - v) - (v - b)

y magnitudes are well-correlated with Johnson-Morgan V magnitudes.

[edit] Mean wavelength and half-widths of response functions

u v b y beta narrow beta wide
Peak wavelength (nm) 350 411 467 547 485.8 485
Half-width (nm) 30 19 18 23 2.9 12.9

[edit] References

  1. Strömgren, Bengt, 1956, Two-dimensional spectral classification of F stars through photoelectric photometry with interference filters, Vistas in Astronomy, Vol. 2, Issue 1, pp. 1336–1346
  2. Crawford, David L., 1958, Two-Dimensional Spectral Classification by Narrow-Band Photometry for B Stats in Clusters and Associations, Astrophysical Journal, Vol. 128 (September 1958), pp. 185–206

[edit] External links

  1. The Asiago Database on Photometric Systems
  2. The uvby photometric system

[edit] See also

Stellar classification

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