Abstract
THE SPECTRUM OF δ CEPHEI.—M. A. Belopolsky has taken a number of photographs of the spectrum of δ Cephei—a variable of short period—and determined from them the velocity of the star in the line of sight. The results obtained showed a periodic variation, and M. Belopolsky used them to find the elements of the star's orbit, in the manner described by Dr. Lehmann-Filhés in the Astronomische Nachrichten, No. 3242 (see NATURE, August 2, p. 327). He finds that the eccentricity of the orbit is 0˙46; and the apparent semi-major axis 180,000 geographical miles (207,000 English miles). The period of the star is 5d. 9h. The maximum velocity of approach is about 28 statute miles per second, and of recession 3˙2 miles per second. The system, as a whole, is therefore moving away from our own system. It is found that the light-minimum occurs one day before the time of periastron passage given by the computed elements of the orbit.
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Our Astronomical Column. Nature 51, 21–22 (1894). https://doi.org/10.1038/051021a0
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DOI: https://doi.org/10.1038/051021a0