Items related to The Observatory Volume 10
Synopsis
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1887 Excerpt: ...given of part of the spectrum of Pollux is a most magnificent example of a stellar spectrum, being on a scale which would separate H and0K by nine tenths of an inch, or about two thirds that employed by Angstrom and Cornu in their maps. Nearly 150 lines are shown in a comparatively short section of the spectrum, with a clearness and definiteness that recalls some even of the best photographs of the solar spectrum. The ability to study stellar spectra on this scale opens out quite a new future for this department of astronomy. On the same plate specimens are also given of spectra taken directly from the original negatives without enlargement. The size and character of the spectra used in the preparation of the catalogue of stellar spectra is illustrated by the spectra of ( Ursae Majoris and the adjacent fifth-magnitude star. An exposure of five minutes was given. One or two hundred such spectra are sometimes photographed on a single plate. The spectrum of Pollux from which the above-mentioned enlargement was made is shown and also one of Vega. Amongst the points of interest which an inspection of the plates of the survey-have brought out, it may be mentioned that a photograph of Mira Ceti shows G and h, together with four lines in the ultra-violet, as bright lines, the four latter corresponding to the well-known series of lines brought out in his photographs of Vega and other stars of the same type by Dr. Huggins. H and K are, however, dark in Mira, so that they would appear not to belong to the same series as the ultra-violet lines. Gore's new variable near Y' Orionis gives a similar spectrum to that of Mira. a Cygni shows H doub'e, the two components differing in wave-length by about a tenth-metre. The last part of the report gives the following informatio...
"synopsis" may belong to another edition of this title.
