Abstract
PROF. PICKERING, while retaining the four types of stellar spectra, finds that so many stars show an intermediate stage of development, that, in the Draper Catalogue, letters are substituted for the types. Thus, let ters A to D denote stars of the first type; E to L, stars of the second type; M, stars of Type III.; while N is reserved for fourth type stars. It seemed of some interest to compare the photographic results with those obtained directly with the spectrosoope. For the first and second types, the observations of Vogel (“Spect. Beob.,”-- 1° to + 20°) were used. The stars in the first four hours of R.A. which occur in both works were examined and tabulated, those being rejected where there was any uncertainty as to type in Vogel's observations. The following table shows the results thus obtained:—
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