Abstract
THE DEARBORN OBSERVATORY.—Prof. Hough's report to the Directors of the Chicago Astronomical Society is as usual chiefly occupied with the observations of Jupiter which have been made with the great refractor. The great red spot still forms, of course, the object of greatest interest. The curious filling up which it underwent last February, whereby for a time it presented the appearance of a reddish elliptical ring, with a white centre, is described, and also its gradual return to its normal appearance. The red spot has now been watched for seven years, and during that time its latitude, shape, and size have undergone but little change. The length, however, appears to have diminished slightly in 1884 as compared with 1883, Prof. Hough's measurements being 12″.29 for 1883, and 11″.26 for 1884. The breadth, on the other hand, seems somewhat greater, so that it is less markedly elliptical than in former years. The mean rotation period for the interval 1884 September 25 to 1885 June 29 was found to be 9h. 55m. 40.4s., or somewhat greater than in previous years. “The depression in the rquatorial belt under the red spot, which was formed in 1882, has continued, but is gradually being obliterated.” “The principal equatorial white spot which has been observed since 1879 was not so conspicuous as in former years.” The old rotation value, 9h. 50m. 9.8s., satisfied the observations.
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Our Astronomical Column . Nature 33, 107 (1885). https://doi.org/10.1038/033107a0
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DOI: https://doi.org/10.1038/033107a0