Per. - From the
ratios 
4045:
H
and
4226:
H and the intensity of
the G band a spectral type of F6 is derived on the system of the
present Atlas. The following features indicate that the spectrum in
the blue region comes from two stars.
1. The CN absorption, having a sharp head at
4215, is present and is
about as strong as in a giant G2 star. This absorption was not seen in
any normal star earlier than G0 examined while preparing the Atlas.
2. There is a broad, faint absorption at
H which makes the appearance
of the region different from that in a normal F6 star. This is
probably due to a broad A-type hydrogen line superposed on the
narrower one.
3. The strongest absorption at K is narrow and is similar to a star near type A5, and there is almost certainly present a faint, broad K line superposed on the sharp one.
The spectral type of the component of later type is probably near G5. Its luminosity class is probably III.
a Equ. - The spectrum is similar to
Per. The
CN absorption toward the
violet from 
4215 is present
and indicates that the later-type
spectrum is near G5. The integrated spectral type at
4000-4300 is
somewhat earlier than Per - about F5 - owing to the greater strength
of the H lines. The A star appears to be somewhat brighter relative to
the later-type component. The line at
4077 is stronger relative to
4045 than in
Per.
Leo. - The CN absorption
near 4215 is not observed and the
later-type spectrum is therefore almost certainly earlier than
G0. This spectrum is combined with one of early type which, to judge
by the narrow K line, is near class A2. The two components form a
spectroscopic binary. The spectrograms used were obtained on April 22,
1942; on them the K line is composite, the sharp A component lying
near the red edge of a faint, diffuse component. The line
4077 is
strong, and from its intensity a similarity in luminosity to an F
supergiant [a Per (F5) or
Cyg (F8)] might be
assumed. The region of
the G band, however, does not have an appearance like that of a
supergiant of type F, and other line ratios suggest a luminosity class
of around II-III. This value is uncertain; it could be determined more
accurately if spectrograms on a high-contrast emulsion were
available. The spectral type of the component of later type is
probably near F6.
a Aur. - The combined spectral type of the two components is G2 II-III. An unpublished determination made several years ago from high-dispersion plates on which the components were resolved gives, on the system of the present Atlas,
The separate values for the two components are very uncertain and may be in error by a considerable fraction of their separation.
Cyg. - The
spectral type of the component of late type is probably K3
II. At the position of K there is a broad, shallow absorption. It is
estimated that the spectral type of the component of early type is
probably earlier than A0. The features described all belong to the
spectrum of Cyg A.