Our Astronomical Column

    Abstract

    THE RECENT SPECTRUM AND MAGNITUDE OF NOVA PERSEI No. 2.—The results of Prof. Hartmann's more recent investigations of the spectrum of Nova Persei No. 2 (1901) appear in No. 4232 of the Astronomische NachricMen (p. 113, February 11). Finding that when the magnitude of the star became less than 10-0 he was unable to photograph the spectrum with the large instrument used in the previous investigation, Prof, hartmann devised a new spectroscope in which the collimator objective, of 40 mm. aperture and 60 cm. focal length, was made of U. V. glass, and the. camera objective was made of quartz, having an aperture of 40 mm. and a focal length of 32 cm.; quartz prisms were employed, and the distance between H/3 and HS on the plate was 4-6 mm. This spectrograph was used in conjunction with the 80cm. refractor, and a good spectrum was obtained with 8j hours' exposure on October 15 and 18, 1907, when the Nova's magnitude was 11-4. The main feature of this spectrum is its similarity to the spectrum of the Wolf-Rayet star B.D. 35°.4001. In both spectra the brightest line is' at A 4688, whilst HP, Hy, and H5 are more faintly shown. The fairly strong line in the spectrum of the W.—R. star at A 4618 is comparatively faint in that of the Nova, whilst the trace of a line in the latter at A 3890 is not to be found in the Wolf-Rayet spectrum. The chief nebula lines at AA 5007 and 4959 are apparently absent from both spectra or are very faint.

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    Our Astronomical Column . Nature 77, 377–378 (1908). https://doi.org/10.1038/077377a0

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