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Hertzsprung's Luminosity-Colour Relation for Visual Binaries

Published online by Cambridge University Press:  14 August 2017

W. S. Finsen
Affiliation:
Johannesburg, South Africa
P. N. J. Wisse
Affiliation:
Johannesburg, South Africa

Extract

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The number of visual binaries for which orbits have been computed now exceeds 600, but this laboriously accumulated wealth of data remains relatively sterile owing to the paucity of reliable parallaxes. Hertzsprung (1964) had this in mind when he revived the idea he first voiced in 1911 and proposed a new luminosity parameter defined as the absolute magnitude of a star reduced to unit mass without changing its density or surface brightness. The great advantage of this parameter is the fact that it is readily derived from the period and semi-major axis of a visual binary without recourse to the parallax. It therefore permits immediate use of most of the computed orbits for the construction of a luminosity-colour diagram analogous to the classical H-R diagram but entirely free of the scatter resulting from errors in the parallaxes.

Type
Session 2. Orbital Parameters
Copyright
Copyright © The University of Toronto Press, Royal Astronomical society of Canada 1973

References

Alexander, J. B. 1970, Mon. Notes astr. Soc. South Africa, 29, 44.Google Scholar
Blanco, V. M., Demers, S., Douglass, G. G. and FitzGerald, M. P. 1968, Pub. U.S. Nav. Obs., 2nd ser., 21.Google Scholar
Finsen, W. S. and Worley, C. E. 1970, Republ. Obs. Johannesburg Circ., 7, 203.Google Scholar
Harris, D. L., Strand, K. Aa. and Worley, C. E. 1963, Empirical Data on Stellar Masses, Luminosities, and Radii in Basic Astronomical Data, ed. Strand, K. Aa., Univ. of Chicago Press, p. 285.Google Scholar
Hertzsprung, E. 1964, J. des Obs., 47, 31.Google Scholar
Knipe, G. F. G. 1969, Republ. Obs. Johannesburg Circ., 7, 197. 1970, ibid., 7, 260.Google Scholar
Smak, J. 1967, Acta astr., 17, 213.Google Scholar