Abstract
INTERESTING BINARY STARS.—Mr. J. S. Plaskett investigates, in vol. i., No. 2, of the Publications of the Dominion Astrophysics Observatory, Victoria, B.C., the orbit of the spectroscopic binary U Coronæ. Both spectra are visible, each being of type B3. The following are the elements of the two stars in terms of the sun, the brighter star being placed first:—Radii, 2.90, 4.74; masses, 4.27, 1.63; and densities, 0.175, 0.015. Taking the surface intensity of the bright star to be -2.7 magnitudes, as compared with the sun, of which the absolute magnitude is 4.86, the distance is deduced as 400 parsecs. It is, however, noted that the fainter star, though of the same spectral type, has only one-eighth of the surface brightness; this indicates that the correlation of surface brightness with type is less close than some physicists have assumed.
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Our Astronomical Column. Nature 106, 772 (1921). https://doi.org/10.1038/106772a0
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DOI: https://doi.org/10.1038/106772a0