Abstract
THE DOUBLE STAR Σ 2120.—In the notes to the last catalogue of measures of double stars of the late Rev. W. R. Dawes, he remarks with reference to Σ 2120, or, as it has been frequently called, Herculis 210 (Bode): “This object discovered by Struve is undoubtedly a binary system—the position varying in a retrograde sense, and the distance diminishing.” Notwithstanding this positive opinion as to physical connection of the components by so high an authority in this department of practical astronomy, an examination of the path of the companion up to the latest published measures of the Baron Dembowski towards the end of 1870, or, it should be stated, through a period of observation fifteen years longer than that upon which the above opinion was expressed, does not support the presumed binary character of the object, but on the contrary, when the apparent fixity of the principal star is considered, shows pretty decidedly that the variation of angle and distance must be owing to proper motion of the smaller one. In fact we may represent the measures, from Struve's earliest in 1829, to Dembowski's in 1870, by the following expressions:—
Article PDF
Rights and permissions
About this article
Cite this article
Our Astronomical Column . Nature 12, 147 (1875). https://doi.org/10.1038/012147a0
Issue Date:
DOI: https://doi.org/10.1038/012147a0