International Astronomical Union

Abstract

THE triennial conference of the International Astronomical Union, representing 27 countries, will be held at Stockholm during the week August 3–10 under the presidency of Prof. E. Esclangon, director of the National Observatory of Paris. After the usual opening meetings, the conference breaks up into a number of committees at which astronomical problems, especially those calling for international co-operation, are discussed. Draft reports from no fewer than twenty-nine such committees have been distributed a month in advance to those attending the meeting. Among the topics to be discussed are standard notations in astronomy–a provisional list of suggested symbols has been circulated in advance–air almanacs, the publication of classical works of astronomy which are untranslated or difficult of access, the sources of error in observations with meridian telescopes and the distribution of fundamental stars for observation to different observatories, co-operation in cinematography of solar prominences to cover longer intervals of time than are available for one observatory, wave-length standards in the laboratory and the solar spectrum, the zero point of photographic magnitude and colour index, problems of stellar statistics and the absorption of light in interstellar space. Reports will be received on the present position of the "Carte du Ciel", of the observations of Eros at the opposition of 1931 and of the observations of radio signals at 71 different observatories in the world scheme of 1933. General discussions will take place in the different special committees on the past and future co-operation in the observations of stellar parallaxes, proper motions, variable stars and novae, radial velocities, solar phenomena and cometary spectra and magnitudes.