Astronomers have historically been among the first to apply or develop, at times, new technologies in the furtherance of their science. This has been especially true in the use of computers from their archaic, antediluvian beginnings to the present highly-developed, time-sharing, multiprocessing, teleprocessing systems. Thus, among the earliest applications in the last half century was the use by L. J. Comrie at the Greenwich Observatory of Hollerith machines for the construction of tables (Comrie, 1928). In 1940 Eckert described punched card methods for numerical integration, computation of a numerical lunar theory, computation of planetary perturbations, as well as applications in photometry and construction of star catalogues (Eckert, 1940). Indeed, one of the earliest collections of files for general use was available at the Watson Astronomical Bureau and included Boss’ General Catalogue of 33,342 stars, A. G. Catalogues, Yale Zone Catalogues, and Kohlschütter’s Catalogue.

When we began to collect systematically photometric data it was felt that we needed an appropriate system of identification for our catalogues on magnetic tape. The current system of identification which uses catalogue or list name and star number is best suitable for printed catalogues but brings out many drawbacks when using and intersecting catalogues on magnetic tapes. Thus we developed a coded system of identification with the two basic conditions that it allows to include in the files stars with all possible Kinds of numbering found in the literature, and that computer use was as simple as possible (Mermilliod, 1973).

The reductions of the direct measurements necessary for obtaining the published positions and proper motions of stars are rather involved. The transformation from equatorial coordinates to galactic coordinates – and proper motion components – is rather simple, and due to the exact definition of the galactic system, galactic coordinates and proper motion components can be given with the same accuracy as equatorial ones. Since it is data in the galactic system which are primarily of interest for the galactic astronomer, it is proposed that much data be henceforth published in catalogues of star positions and proper motions. One may assume that the minority of astronomers who need the data in the equatorial system will be least likely to make mistakes in transforming them back to the more direct form in which they were observed.

It is further suggested that the SAOC could be used as a base for continuous improvement and updating of a comprehensive catalogue of star positions, to be updated by the incorporation of newly available material every other year or so. Procedures by which this would be accomplished are indicated.

A comprehensive bibliography of astronomical catalogues for the period 1951-75 inclusive containing over 2000 items and including an index of designations has shown that there is an urgent need to control the use of designation notation. It is suggested that a small data base, similar to the one created for this bibliography could serve as a useful guide to the assignment and subsequent citation of catalogued objects. This in turn would help those compiling inverted files of stellar objects such as the Catalog of Stellar Identifications.

Collecting all the data and references for a given star is generally a very time-consuming task, because the star may have many identifications. It is therefore a very first need to know the various identifications which may be used in the primary literature concerning a given star, in order to retrieve the whole set of information about the star.

The Catalogue of Stellar Identifications (CSI), which tries to solve this problem of cross-identifications, is therefore the fundamental file of the Stellar Data Center. It was created five years ago by J. Jung (1971), who was the first Director of the Center, with the help of Madame Bischoff and Madame Morin. The CSI was first a merging of some fundamental catalogues: SAO, HD, AGK2, CPC (Cape Photographic Catalogue for 1950), YZ (Yale Zone Catalogue), and GC. For each star, the information was the following:

In 1969 the second edition of the “Catalogue of Nearby Stars” was published. It contains 1529 single stars and systems with a total of 1890 components. The catalogue lists all stars with parallaxes equal to or larger than 0.”045. Only 1049 of these objects are nearer than 20 pc. The “Catalogue of Stars within 25 pc of the Sun”, published 1970 in the Royal Observatory Annals No. 5 consists of 1744 systems of which 1566 trigonometric parallaxes.

The number of new lists of stars and stellar objects published each year increases rapidly. From the designation of a star it is often difficult to trace back the original list or the basic data relevant to the star or stellar object. Designations are sometimes ambiguous. A few proposals are presented to try to improve the present situation.

The principal features of the International System of Units (SI) are briefly described and the advantages of its wider adoption in astronomy are discussed. The need for the continued use of a system of astronomical units for some purposes is recognised.

With the increasing use of electronic rather than photographic data collection, and on-line minicomputers at the telescope, two factors will necessitate a reconsideration of the way in which data are stored at the telescope.

1) Many of the electronic data collecting methods produce data in a final or semifinal (digital) form and usually with a large dynamic range; high-data-rate digital recording devices at the telescope are increasingly necessary.

2) Minicomputers allow quality control of data and often complete data reduction either in real time or with a very short time delay. We shall consider both these factors in some detail, emphasizing some of the many possibilities inherent in the increasing availability of one- and two-dimensional array detectors and mass storage devices. But let us first briefly examine the “classical” data gathering techniques. As in the later discussion, we shall subdivide the field into high-resolution spectroscopy, low-resolution spectroscopy (including multicolor photometry), surface photometry of extended objects, and positional astronomy.

The sensors on a spacecraft, the spacecraft data handling system, the mission support ground data system, the experimenter’s scientific data reduction and analysis system, the post-mission data storage and dissemination system all comprise elements of the data handling system for a space-based astronomy.

Primary treatement is given to the experimenter’s scientific data system where the following aspects of astronomy missions are discussed: increasingly close operational contact of the experimenters with the sensors calls for moving data processing operations to the earliest possible point of the system. On the other hand, potential need for subsequent reprocessing of data would favor the central ground-based facility for initial processing with the open-end system philosophy.

One approach, extant and planned implementation of the scientific data analysis system for the zodiacal light experiment of the solar probe Helios, is presented in detail, taking into consideration experience from the various astronomy missions, in particular Pioneer and Skylab.

Since 1970 the Westerbork Synthesis Radio Telescope has been collecting data on galactic and extragalactic fields. The data is stored and cataloged on magnetic tape using a standard format. This data is routinely reduced and analyzed at different observatories in Europe. A reduction program package allows manipulation and display of the data. After the initial reduction all tape output from the reduction programs uses the same tape format regardless of the program. Transportation of data between observatories is done via magnetic tape with the same standard format. For data transportation to observatories not normally using Westerbork information a common tape format has been developed. Suggestions to alleviate problems with this data transfer are discussed.

Preliminary results of a search for observational data of radio sources are presented. Emphasis is put on those items which are imperative to make such a data collection amenable to astrometrical exploitation with a view to the identification of optical and radio positions, and the selection of suitable radio stars as reference points for other galactic and extragalactic objects.

An ultraviolet photometric system based on observations obtained from the ultraviolet Sky Survey Telescope in the TD1 satellite is described. The system considered here consists of ultraviolet magnitudes at λ1 = 2740A, λ2 = 2190A and λ3 = 1490A. The extinction free parameters derived from the observed ultraviolet colours enable determination of interstellar reddening, spectral type and luminosity. This photometric system has been evaluated by comparing these parameters with other classification parameters.

At the University of Texas we are working on the reduction and analysis of ultraviolet stellar spectra obtained with the S-019 experiment on Skylab (Karl Henize, principal investigator). Our objective prism photographs recorded nearly 10,000 stars at wavelengths shortward of 3000Å, many of them of 9th or 10th visual mag., and for proper analysis we need to assemble ground-based data into a workable master catalog. The most immediate application of this catalog will be computer simulation of the ultraviolet photographs in order to point out significant anomalies with respect to previous knowledge. We need to have a catalog, then, which is as complete as possible in terms of the existence of early-type stars to at least 10th mag., their spectral types, photometry, known peculiarities, duplicity, and so forth. Also the master catalog must contain only a single value for each magnitude and for the spectral type, rather than a listing of various determinations, in order to be useful for the simulation. This means that auxiliary data files are needed for recording data in more detail so that the master catalog may be kept at a workable size, while at the same time the basic data are readily available.

Many catalogues of astronomical data appear in book form as well as in a machine-readable format. The latter form is popular because of the convenience of handling large bodies of data by machine and because it is an efficient way in which to transmit and make accessible data in books which are now out of print or very difficult to obtain. Some new catalogues are prepared entirely in a machine-readable form and the book form, if it exists at all, is of secondary importance for the preservation of the data.

In this paper comments are given about the importance of prefaces for transmitting the results of a critical evaluation of a body of data and it is noted that it is essential that this type of documentation be transferred with any machine-readable catalogue. The types of error sometimes encountered in handling machine-readable catalogues are noted. The procedures followed in developing the Goddard Cross Index of eleven star catalogues are outlined as one example of how star catalogues can be compared using computers. The classical approach to evaluating data critically is reviewed and the types of question one should ask and answer for particular types of data are listed. Finally, a specific application of these precepts to the problem of line identifications is given.

Some problems encountered in the homogenization of photometric data (especially for the uvby$ and UBV systems) are presented: sources of inhomogeneity, method to obtain a homogeneous photometric value, establishment of a reference list, etc.

In many cases a homogeneous photometric value is necessary, but cannot be simply an arithmetical mean, and for this purpose it is necessary to make a critical evaluation of the data.

Several astronomers were relaxing after a hard day at the I.A.U. when the talk got around to their research activities. One said, “There is a red star found in the Lowell proper-motion survey that seems rather interesting – it is G232-75, which has a proper motion of almost a second of arc per year. Since Giclas1 catalogue doesn’t give any spectral type I’m planning to go to Kitt Peak to observe it. The trip only costs about 300 dollars, and besides it’s fun to visit Arizona.”