Abstract
THE INTRA-MERCURIAL PLANET.—In addition to the letter addressed to the Astronomer-Royal by Prof. James Watson, after revising his first position of the object near θ Cancri, more carefully at Ann Arbor, similar communications have been made to M. Fizeau (Comptes Rendus, May 2), Prof. Forster (Circular zun Berliner Astronomischen Jahrbuch, No. 98), and to Prof. Peters (Astronomische Nachrichten, No. 2,217). The definite position is in R.A. 8h. 27m. 243., Decl. + 18° 16′ for July 29, at 5h. 16m. 37s. Washington M.T., or 10h. 24m. 49s. M.T. at Greenwich, which position Prof. Watson considers to be trustworthy within five minutes of arc, with a greater probable error in the declination than in the right ascension. The other points named by the discoverer, upon which stress is to be laid, are the fact of the star θ Cancri being also observed, the appearance of a sensible disk with a power of 45 on a 4½-inch refractor, its ruddy colour and much greater brightness than that of the neighbouring star. There has never been a suspicion of a variable star in this vicinity, nor can the appearance of a disc be so explained. Prof. Watson seems to have satisfied himself that the object was not a comet; indeed, such a body would hardly appear round and well-defined with the. sun totally eclipsed. In the case of the comet of March 1847, which was observed in full daylight, at a similar distance from the sun to that of Prof. Watson's object, two short tails were visible though the head was circular, and the great comet of February, 1843, also exhibited a bifid tail, which was bright and distinct to the naked eye. Mr. Hartnup, who observed the comet of Klinkerfues, 1853, in broad daylight, described it as circular, well-defined, and without tail, but the case is hardly analogous to that of a comet viewed while the sun is wholly hidden.
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Our Astronomical Column . Nature 18, 552 (1878). https://doi.org/10.1038/018552a0
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DOI: https://doi.org/10.1038/018552a0