Abstract
MICROMETRIC MEASURES OF JUPITER AND SATURN.—In the recently-published “Observations,” made at the Hong Kong Observatory during 1886, Dr. Doberck gives some measures of Jupiter and Saturn made with the 6-inch Lee equatorial now at Hong Kong. The measures of Jupiter, extending from August 29, 1879, to April 7, 1886, include the position-angle of the polar axis, the apparent equatorial and polar diameters, the breadth of the equatorial belts and of the red spot, and the length of the latter when on the central meridian. Dr. Doberck concludes that the equatorial and polar diameters at the mean distance of Jupiter are 38″.207 and 35″.942 respectively, and that the equatorial semi-diameter at the mean distance of the earth from the sun is 99″.39. The measures of Saturn extend from January 3, 1879, to April 5, 1886, and include the position-angle of the polar axis, the external diameter of the ring, the diameter of Cassini's division, the internal diameter of the ring, and the equatorial and polar diameters of the planet. The deduced dimensions at the mean distance of Saturn are:— External diameter of ring 40″.28, diameter of Cassini's division 34″.42, internal diameter 26″.82, equatorial diameter of Saturn 17″.22, and polar diameter 16″.53. The equatorial semi-diameter at the mean distance of the earth from the sun is 82″.11.
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Our Astronomical Column . Nature 36, 65 (1887). https://doi.org/10.1038/036065a0
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DOI: https://doi.org/10.1038/036065a0