Identification of the post-maximum lines in the spectrum of Nova (RS) Ophiuchi.

Interest in the spectra of recurring novae has been aroused by the recent (fourth) outburst of Nova (T) Pyxidis. A review of the hitherto unpublished measures of the Mount Wilson spectrograms of Nova (RS) Ophiuchi obtained between September 2 and November 10, 1933, shows many plausible identifications of lines which were impossible earlier.
The atoms now identified, in addition to H, are: He I, He II, C III, [N II], N m, [O I], O III, [O III], [Ne III], [Ne IV], Na I, Si I, Si II, Si III, Si IV, [S II], [S III], [A V], [A X], [A XI], [K IV], [K V], [Ca V], [Ca VI], [Ca VII], [Ca XIII], [Sc VII], [V VIII], Fe II, [Fe II], [Fe IV], [Fe V], [Fe VI], [Fe VII], [Fe X], [Fe XI], [Fe XIV], [Ni XII], [Kr III]. Of these, [A XI] λ 6919, [Ca VII] λ 3688 (and possibly [V VIII] λ 3686), [Sc VII] λ 4823, and [Kr III] λ 6827 are identified for the first time.
Considerations of the physical conditions in the solar corona as compared with those in the recurrent novae indicate marked differences, the coronal strata not permitting radiation of forbidden lines in the lower stages of ionization such as are found in the novae.