Note on the Spectrum of Brorsen's Comet

Abstract

ON April 1 and 2 I succeeded in determining the position of the green band in the spectrum of Brorsen's comet. The spectrum was so faint that the other bands could not be measured. The instrument was the 91/2inch equatorial of our astronomical laboratory, armed with a one-prism spectroscope. The observations were made by bringing an occulting bar, movable by a micrometer screw, into such a position that the well-defined lower (less refrangible) edge of the band in the comet spectrum should be just visible as a thin line, the rest of the band being hidden by the bar. After the pointing the flame of a Bunsen burner was brought in front of the slit, and the position of the band in the comet-spectrum was thus fixed.