Abstract
SCHMIDT'S VARIABLE STAR NEAR SPICA.—On June 6, 1866, Dr. Julius Schmidt remarked to the south and east of Spica a conspicuous star which he estimated 5.4m., and which was wanting in Argelander's Uranometria. It was brighter than the neighbouring reddish-yellow star, 68 Virinis. He found its place for 1866′0, R.A. 13h. 27m. 33s., Decl. — 12° 31′5. It is Lalande 25086, estimated 6.7 on May 10, 1795, and Piazzi XIII. 126, called 8m. in the catalogue, but 7 and 6.7 in the Storia Celeste. It was not observed by Bessel nor Santini, but occurs in Lamont's Zone 355, 1846, May 22, when it was rated 8m. In Bremicker's Berlin Chart it is 7m., and 6.7 in Heis. But a special point of interest about this object is Schjellerup's inference that it is identical with the 19th star in Virgo in Ptolemy's Catalogue, as indicated in a note at p. 160 of the translation of the Catalogue of Abd-al-Rahman al-Sûfi, which the Persian astronomer says was of the smaller fifth magnitude, nearer the sixth, though Ptolemy calls it “absolutely of the fifth.” In Baily's edition of Ptolemy's Catalogue in vol. xiii. of the Memoirs of the Royal Astronomical Society, the star in question is No. 515, and there identified with 68i Virginis: it is called δ νoτιώτερos τηs ξπoμεvηs πλευρâs. Schjellerup, translating from Al-Sûfi, says: “La 19e est la méridionale du côté postérieur du quadrilatère, après al-simûk, s'inclinant vers le sud; elle est des moindres de la cinquième grandeur; Ptolémée la dit absolument de cinquième, mais elle est plus près de la sixième. Entre elle et al-simâk vers le sud-est, il y a environune coudée et demie et entre elle et la 17e il y a la même distance. Avec al-simâk et la 17e elle forme un triangle isoscèle, cette étoile étant au sommet. La latitude de cette étoile, indiquée dans le livre de Ptolémée, se trouve erronée, parce que, au ciel, elle se fait voir autrement qu'elle ne tombe sur le globe. Car, d'aprés cela, elle devrait se faire voir au nord d'al-simâk, tandis que, en verité, elle se trouve au sud.” Al-simâk is Spica, and the 17th star appears to be 76 Virginis. Baily in his Catalogue places the 19th star in longitude 178°, with 3° o' south latitude, but in a note he points out that in the edition of Ptolemy, published by Liechtenstein at Venice in 1555, the latitude is o° 20′ and north; with the remark, “The star 68 Virginis agrees with the position given by Ptolemy; but it is difficult to make it accord with the description, as being in the ‘latus sequens’ of the quadrilateral figure.”
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Our Astronomical Column . Nature 27, 617–618 (1883). https://doi.org/10.1038/027617a0
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DOI: https://doi.org/10.1038/027617a0