Abstract
TUTTLE'S NEBULA, N.G.C. 6643.—In this column for September 25 last attention was directed to M. Borrelly's observation of Hind's nebula indicating its variable nature. M. Borrelly has recently been making observations on the nebula of Tuttle, N.G.C. 6643, at the Marseilles Observatory, and has communicated the results to the Comptes rendus for December 22, 1913 (vol. clvii., No. 25, p. 1377). He brings together all the observations made since its discovery in 1859, and the evidence is distinctly in favour of its variability. In very recent years, i.e. in 1909, its light appeared to diminish considerably. From 1910 to 1912 it was feeble, but still to be seen in the comet-seeker (mag. 11). On July 10, 1913, M. Borrelly says it was scarcely visible in the instrument; on August 26 it was at the limit of visibility, while on August 27 it was practically invisible (mag. 11-5). From the observations M. Borrelly concludes that changes have taken place.
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Our Astronomical Column . Nature 92, 540 (1914). https://doi.org/10.1038/092540a0
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DOI: https://doi.org/10.1038/092540a0