The Current Revision of the Solar Spectrum Table λ 2935 Å to λ 8770 Å

Abstract

The current edition of The Solar Spectrum Table is nearing completion. All wavelengths have been corrected to conform to the 1928 scale of International Standards. For some 6500 lines, new measurements have been used in deriving the final weighted means recorded in the Solar Table.

Equivalent widths have been determined by Minnaert and his staff for all lines listed, except 152 atomic lines that are absent from the disk spectrum, but present in the sun-spot spectrum.

The intensity behavior of individual lines in the spot spectrum as compared with the disk spectrum is briefly described in a separate column under letters that indicate whether the line is strengthened, weakened, unchanged, or obliterated in the spot spectrum.

The revised identifications for atomic lines have been made from the data assembled for the program on Atomic Energy Levels. They are based on a study of series and multiplet structure as far as possible. The lower excitation potential and multiplet number are given for the individual lines.

A revision of identifications for molecular lines has also been made for the leading molecules present in the disk spectrum. Tables of approximate counts of these lines in the solar spectrum are given for OH, NH, CN, CH, C2, and MgH. The rotational line and vibration band are indicated in respective columns for each molecular line present in the solar spectrum. The electronic transition can be found in an auxiliary table under the note number in the last column of the Solar Table.

The present total number of lines listed, including the atomic spot lines, is about 22000 (over a longer range) as compared with about 20000 from Rowland’s Table, listed in the 1928 edition. To date 71 percent are wholly or partially identified, as against 57 percent in 1928.

A general summary of elements present in the sun is discussed. There are 62 present without question, and 4 whose presence is subject to question. Two additional elements, B and F, whose presence has been reported from evidence afforded only by molecular spectra, require further study.