The Variable Stars Bureau of the Astronomical Council of the USSR Academy of Sciences presents this paper in order to provide information on our work with the hope that it will be discussed and recommendations to it will be made. More rational co-operation of our Bureau and the Strasbourg Centre de Données Stellaires is highly desirable. It should be based on the exchange of information gained in these centres in order to make both centres free from duplicating work.

Photometric observers have from time to time expressed the need for a convenient way of finding in the literature the photometric sequences they require. This need is particularly felt in photographic photometry, and the increasing use of the Palomar Sky Survey in recent years, and more recently the ESO and SRC surveys, have given a new impetus to the subject. In addition, the use of image tubes has led to a further demand for suitable calibration sequences.

There are two centres at which papers on spectroscopic binaries are filed and catalogues produced — Toulouse, France and Victoria, B.C., Canada. The aims of these two are somewhat different. At Toulouse a running file of all references to spectroscopic binaries is kept, and many workers have found the comprehensive series of Catalogues Complémentaires (e.g. Pedoussaut and Carquillat 1973) very useful. At Victoria, on the other hand, we concentrate more specifically on spectroscopic determinations of orbital elements, and our catalogue of them was a direct successor of the five such catalogues published by the Lick Observatory. While the Toulouse catalogues are comprehensive, we at Victoria try to make a critical assessment of each orbit we include, and we regard this as one of the most important aspects of our catalogues. Such a critical catalogue obviously cannot be published as frequently as are the Catalogues Complémentaires, which, just as their name implies, are complementary to the Victoria work. There is no fixed interval between the publication of successive Lick-Victoria catalogues. The five from Lick appeared at a mean interval of about a decade, but the transfer to Victoria delayed the appearance of the Sixth Catalogue (Batten 1967) to almost twenty years after that of the Fifth (Moore and Neubauer 1948). After another decade, the Sixth Catalogue is out of date and out of print, and we are well advanced on the preparation of a Seventh, which we hope will appear in 1977. The Sixth Catalogue contained orbital elements for 737 spectroscopic binary systems. About 200 (or 25 per cent) new systems have now to be added, and about one per cent of those already in should be deleted. In addition, new orbital information is available for over 100 of the systems already in the Sixth Catalogue.

For many years, the study of close double stars seemed somewhat remote from many astronomical problems. The specialists in the field pursued it with enthusiasm, regarding each light or velocity curve as a particular challenge and each system as unusual and interesting in its own right. However, the relation to most other branches of astrophysics sometimes seemed remote. In favorable cases, masses and radii (and hence mean densities) could be obtained and the mass-luminosity relation could be strengthened; even this advantage was partially negated when it was early realized that in many cases the fainter components were notorious violators of the relation established by visual binaries (i.e., systems well separated compared to those discussed here). Various complexities, connected chiefly with interaction effects between the close components, prevented their use for the extremely precise determinations of limb darkening which at one time seemed possible. Other difficulties have prevented the determination, with the precision once comtemplated, of details of internal structure from the apsidal rotation.

Almost any star catalogue becomes obsolescent as soon as it comes off the press. It is now twelve years since the third edition of the Yale Bright Star Catalogue was published in 1964. In the intervening years numerous important new results have appeared, notably the Jaschek et al Catalogue of MK Spectral Classes, the Lick Double Star Catalogue, the U.S. Naval Observatory Catalogue of UBV Magnitudes, the Abt and Biggs Bibliography of Radial Velocities, the Third Edition and three Supplements of the General Catalogue of Variahle Stars, the SAO Catalogue with proper motions reduced to the FK4 system, several new lists of spectroscopic binaries, and a great many shorter compilations. Consequently well in excess of 20,000 entries in the third edition of the Bright Star Catalogue need up-dating.

Before answering, or trying to answer, the question “how to distribute astronomical and astrophysical data”, it is necessary to reply briefly to the question “why distribute these data?” This question is not so trivial as it first appears and it even hides the basic problem.

Data acquisition in itself is a single or manifold technique, often very delicate, constituting in itself a whole field of research. The interpretation of data follows it and will not necessarily be made by the same people. Very often only one possible aspect will be examined. It is consequently absolutely necessary that the data should be disseminated as widely as possible in order that they are used to the utmost. If it is necessary to assure the dissemination of data, it is no less necessary to ascertain their conservation. I shall give here only one example: the observations which have permitted to obtain the light curve of the quasar 3C273.

A computerized astronomical data retrieval system, based on the Goddard Cross Index of star catalogs and operable from a remote terminal, has been developed. It permits retrieval of stellar data as a function of the object’s identification numbers, descriptive parameters (magnitude and/or spectral type), or position in the sky. In addition, software has been developed to retrieve the full data entry from any of the eleven catalogs currently included in the Goddard Cross Index, such as the Yale Bright Star Catalog (YBS), the Boss General Catalog (GC), and others all in one computer run.

Four catalogs (Smithsonian Astrophysical Observatory Star Catalog (SAO), The Revised New General Catalogue of Non-stellar Astronomical Objects (RNGC), Reference Catalogue of Bright Galaxies, and Two-Micron Sky Survey) have been sorted by Palomar Sky Survey plate area and precessed to the epoch of the specific plate. For any set of coordinates covered by the Palomar Survey and the Whiteoak Extension, the computer can provide all the plate numbers on which the position can be found. These plate areas can be immediately accessed by computer; listings or plots to any desired scale of any or all of the objects from the four catalogs can be provided.

It has been nearly 70 years since Dreyer completed his famous NGC and IC compendia of all the 13,000 non-stellar objects known in his time. Since then, the number of these objects known has increased by an order of magnitude, but this knowledge is scattered throughout the astronomical literature in such a way that it 1s nearly inaccessible from a practical standpoint to any individual.

The present work is an amalgamation of all known catalogs of non-stellar objects, in a uniform, easily readable form. It is Intended not only for astronomers, but also for scientists and engineers in other fields who have need for rapid access to this basic reference data. The types of objects included are galaxies (including both normal and all specialized types such as interacting, peculiar, dwarf, Seyfert, etc.), clusters of galaxies, nebulae of all kinds (planetary, reflection, emission, absorption, etc.), blue objects, groups of stars (open and globular clusters, associations, rings, chains, etc.), quasi-stellar objects, super-novae and others. The Information given for each object includes name, 1950.0 position, angular diameter in arcseconds, magnitude, description, and original reference. A portion of the work is shown in Figure 1. Approximately 185,000 listings appear in the full master 11st.

Bibliographic work was begun in 1969 on Interstellar Matter and Galactic Non-Stellar Objects, mainly those found in regions suspected to be favourable to star formation.

We are contemplating the systematization and automatization of this work, taking advantage of the tools now worked out for stellar data at the Centre de Données Stellaires de Strasbourg.

Due to the increasing amount of the literature about stellar studies, the gathering of the published information about a given star becomes a tedious and time consuming task. For enabling an automatic retrieval of information, a bibliographic file has been built in machine readable form through collaboration between Paris and Strasbourg Observatories. The file begins with the year 1950, and is kept up to date. Knowing the name of a star, a program prints the titles of the papers quoting this star. However, only the main journals were covered at first, and some other limitations have been imposed. The first part of this file will be very soon published on microfiches. Meanwhile the information can be obtained from the Strasbourg Stellar Data Center, (Centre de Données Stellaires).

The historical development and current status of the two visual double star catalogues maintained at the Naval Observatory are discussed.

Systematic differences in trigonometric parallaxes between Allegheny Observatory and Yale Observatory, between Allegheny Observatory and McCormick Observatory and between the Cape Observatory and Yale Observatory have been investigated for stars common to each pair. The differences found correlate with right ascension, naturally suggesting some sort of annual influence. It is proposed that these differences are related to differences in the annual temperature cycle between observatories, possibly through the mechanism of temperature dependent decentering of the telescope objectives. A dependence upon spectral type was also discovered in the differences between the relative parallaxes from Allegheny and from Yale. Further work is needed to clarify the nature of these systematic effects and to insure that they do not significantly bias available trigonometric parallaxes.

It is proposed that a new parallax catalogue be constructed at Yale after a thorough statistical analysis of all available trigonometric parallaxes has been made. We solicit suggestions and recommendations from interested users.

In spite of the relatively large size of the astronomical community in Japan, there have been rather few efforts to organize an astronomical data system(s) and to take advantage of such systems. As a matter of fact, it has been realized that astronomical data, as the volume grows, are in many cases easier to handle in computer readable form than in printed form, and there is a growing trend of recording observational data or large tables on magnetic tapes and the likes, and of acquiring such data from other investigators (notably from investigators in other lands). However, it has not always been realized that machine-readable data bring about various kinds of problems when they are to be used by a number of astronomers whose fields of interest are different from each other or who works at geometrically scattered insitutions.

The Pulkovo Observatory computing laboratory began its activities in 1956. Originally it was equipped with card-punched machines. An essential work of processing astronomical data was carried out with the help of these machines ([1] and other).

With the development of the computing techniques in the USSR, the laboratory has been equipped with more modern computing devices. At present the Laboratory disposes of the third generation computer ES-1020 of the Ryad type, as well as the second generation computers Minsk-22 and Nairi-K.

The history, contents, and method of distribution of the astronomical data files of the Naval Observatory are described. Some of the cooperative efforts to deal with the “data explosion” are discussed.

The purpose of the present paper is to present a review of the existing data centers.

If one knows nothing about a subject, one makes an enquiry, and this is exactly what I have done. The list of addresses to start with was provided by Dr. G.A. Wilkins, chairman of the Working Group on Numerical Data of IAU Commission 5, who had collected a list of data services. I want to thank all colleagues who have answered the questionnaire, which is the basis of the present paper; the answers (and the questionnaire itself) are reproduced in Appendix A of this paper.

Two IAU data centers, one at the Lowell Observatory and the other at Meudon, were organized in the early 1960s for the purpose of establishing a collection of planetary data and images accessible to all qualified scientists. These centers trace their origin to an IAU resolution sponsored by Commission 16 in 1961. Ours at the Lowell Observatory, known as the Planetary Research Center, was also recommended by the U. S. Lunar and Planetary Missions Board and by the U. S. Space Sciences Board Panel on Earth-Based Planetary Astronomy. Since its inception, our Center has been supported by a grant from NASA Headquarters.

For the convenience of astronomers who need information concerning certain stars but prefer not to search through hundreds of research articles in the hope of finding it, a file of MK spectral types and UBV photoelectric photometry is maintained at Dearborn Observatory. A generous donor made possible the publication in 1974 of a listing of approximately 17,000 IBM cards of data compiled by Pamela M. Kennedy and William Buscombe during 1963-1973.

There are two main modes of data-centre operation – the passive and the active. In the passive mode the data are received, catalogued and stored, and some are later copied and distributed in response to specific requests. In the past the passive mode has been represented by the many printed volumes of observational data in astronomical libraries, but the techniques of data acquisition are now such that it is often no longer practicable, even if it were desirable, to print the very large amounts of observational data that are now produced by modern instruments. In the active mode of data-centre operation the centre collects data that it considers to be useful, then evaluates, combines and analyses them, and finally publishes the results of this work. In the past the active mode has been common in astronomy, and the general catalogues of stellar data are examples of this mode of operation, but each one has required many years of effort. Modern computer systems can, however, store large amounts of data and can display, manipulate and copy them very quickly; it is now possible to combine data of many different kinds and to analyse them together, with the prospect of giving new knowledge about the systems being studied.

The conference now about to be concluded has presented a wide spectrum of coordinate efforts, of accomplishments, projects, and viewpoints. As is only natural and even purposeful in a first colloquium of this scope, there are also some loose ends which we hope to tie together later. Many experienced scientists found it worth participating in the subject which is more organization rather than primary research, and this is a very encouraging feature. Most of us will have deplored, in one context or other, the lack of reliable data compilations; yet not much could be done before efficient computer and storage facilities were at hand, and we may also have nourished the hope that someone else would undertake the tedious and often thankless job of compilation. We are grateful that the invitation to convene the first Numerical Data conference came from the Strasbourg Observatory, where a large-scale and multi-purpose program has been successfully developing in recent years.