At the XVIth General Assembly, Commission 40 decided to curtail its triennial reports, confining them to aspects and developments which do not naturally find a place in the report of another commission. In letters to Presidents of eighteen commissions our new policy was explained and Commission 40 members willing to serve as radio astronomy contact person with one of these commissions were introduced. All Commission 40 members received notice of our intentions, with the names of the contact persons and an outline of this report in September 1978. We trust that from now on research at radio observatories will be integrally reported in the thematically appropriate reports of relevant commissions.

The title of our Commission was last changed in 1964 from “Commission des Etalons de Longueur d’Onde et des Tables de Spectres” to the present title recognizing the broader scope of the Commission. This was initiated by new observing techniques and refined theoretical models. In 1966 it was decided to add two more objects to the work of the Commission: Broadening of spectral lines and collision cross sections. The present structure of the Commission dates back to 1970. Since then the work of the Commission is not well described by the name “Fundamental Spectroscopic Data”. This is a hindrance in the recruitment of new members, especially those who represent new fields of interest. But the answers to an enquiry about change of name were so divergent within our Commission that so far no action was taken.

The Data Center on Atomic Transition Probabilities at the National Bureau of Standards, Washington, D.C., has continued its bibliographical and critical compilation work on transition probabilities. A new general bibliography has been published, covering the literature references through October 1977 (1).

It can be considered as very satisfactory and a sign of good health that, as early as 1961, and since then, the question of the role of our Commission was discussed and in particular the overlapping activities with those of COSPAR and of other IAU Commissions were put into focus. It is the opinion of some members of our Commission that an analysis of whether a partial merging of Commission 44 with COSPAR Working Group 3 should be considered. Such an organizational scheme might offer the advantage of a greater flexibility and of a closer cooperation between IAU and COSPAR in space astronomy with the guarantee that duplication is prevented. Similar schemes do exist in other ICSU organizations.

Stark broadening (1) and polarisation shift effect in high density plasmas (2) have been reviewed. Critical reviews and a tabulation of selected data of the Stark widths and shifts of lines of non hydrogenic atoms and ions have been published (32,33).

The precise value of the Hubble constant, Ho, is today a matter of considerable controversy. The well-known stuay by Sandage and Tammann is published in a series of papers in the Astrophysical Journal from 1974 to 1976. Briefly, Sandage and Tammann determine distances to nearby galaxies in which cepheid variables can be observed. In thoee galaxies, of presumably known distance, they measure the linear diameters of the largest HII regions (which they find to be correlated with galaxy luminosity class). Using these data as calibration, they find distances, and hence absolute magnitudes, of more distant spirals of various luminosity classes from the angular sizes of their largest HII regions, thereby providing a new calibration of the luminosity-class-absolute magnitude relation for Sc spirals. Finally, they use the new calibration to determine distances to still more remote Sc spirals of recognized luminosity class, and whose radial velocities are presumed to be great enough to be indicative of the cosmological Hubble flow. Prom various treatments of their data, they find values for Ho in the range 50 to 55 km s1 Mpc1.

In view of the broad range of topics covered by Commission U8 and the consequent inevitable overlap with other commissions, it/is not feasible to produce a comprehensive self-contained report. The commission therefore restricts its report to a selected list of accessible recent review articles and conference reports, wherein up-todate summaries of various topics can be found. Such a list is given below. A special report by I. S. Shklovsky on work done in the Soviet Union follows.

The ongoing program of the Atomic Energy Levels Data Center (National Bureau of Standards) to produce new compilations of critically evaluated energy level data is at present focused on the first thirty elements. The most recently completed compilations in this series give energy levels for all the spectra of Mn (Mn I-XXV) (1), Cr (Cr I-XXIV) (2), V (V I-XXIII) (3), Ti (Ti I-XXII) (4),Ca (Ca I-XX) (5), and Al (Al I-XIII) (6), and work is underway on the spectra of K and Mg. C.E. Moore’s “Selected Tables of Atomic Spectra” now include 0 1 (7), 0 VI, O VII, and O VIII (8), work on the tables for the remaining oxygen spectra is in progress. A finding list for lines of the multiplets in Sections 1-7 of Moore’s NSRDS-NBS 3 series has been compiled by Adelman et al. (9). A recent publication of the AEL Data Center, “Atomic Energy Levels - The Rare-Earth Elements” (10), gives energy-level data for 66 spectra of the 15 elements La through Lu (Z=57-71), including a number of astronomically important spectra. A review of rare-earth spectral data by Blaise et al. (11) gives partial tables of energy levels and wavelengths and includes data on hyperfine-structure and isotope shifts. The first version of a much needed new compilation of “Line Spectra of the Elements” has recently been published (12). These tables contain some 42,000 lines, including the stronger lines of the first and second spectra of 98 elements and lines of the third, fourth, and fifth spectra for about half the elements from the vacuum ultraviolet to the far infrared. Outred (13) has compiled 8885 selected lines of 57 elements in the infrared region 1-4 pm, with energy-level classifications being given where available. Energy-level and Grotrian diagrams for the atoms and positive ions of the elements H through P (Z=l-15) have been prepared by Bashkin and Stoner (14), and further publications for the heavier elements are planned. The AEL Data Center (NBS) expects to publish in 1979 a “Bibliography on Atomic Energy Levels and Spectra” for the period July 1975 through December 1978 (15). Edlen’s 1976 review of term analysis of atomic spectra has references for spectra of the elements He through Ni (16), and Adelman et al. (17) have compiled an astronomically oriented bibliography on atomic autoionization. A bibliography on experimental isotope shifts in atomic spectra by Heilig (18) gives 666 references.

Molecular spectroscopic activity, and its literature, has continued to proliferate strongly during the reporting period. There has been much work over the entire wavelength range: microwave - extreme ultraviolet. The impact of the methods of laser spectroscopy on the field, and developments in molecular lasers have continued to provide a great stimulus to molecular spectroscopic research. There has also been increasing recognition of the need for fundamental spectroscopic data of all kinds in astrophysical, atmospheric and enviromental research applications. The scope of contemporary interests is displayed in the programme books for the symposia on Molecular Spectroscopy held annually at the Ohio State University. For the past three years the literature of the molecular spectroscopy has been so prolific that it is impossible to make a definitive review even of the astrophysically important contributions beyond brief citations. Important trends are indicated below. Literature citations have been principally compiled from the reports received from individual workers in Centres of Research on molecular spectra.