1 Introduction

This paper is the continuation of earlier studies devoted to the geographical distributions of observational activities for astronomy (Heck 1998b) and of astronomy-related organizations (Heck 1998c). Among other trends, these papers have illustrated that the well-known socio-economic effect of self-reinforcement is also taking place in the worldwide astronomy community.

The current contribution investigates the age of the astronomy-related organizations, be they professional, for amateur and grand public, or linked to astronomy through their activities or through the products they manufacture and distribute. To our knowledge, this is the first study of this kind.

As in the previous papers, the data originate from the master files for StarGuides (Heck 1998a) and StarWorlds (Heck et al. 1994), the latter one being the WWW version of the former one which is a classical directory on paper (for a detailed presentation, refer to the previous studies or to Heck 1997). The files are gathering together all practical data available on associations, societies, scientific committees, agencies, companies, institutions, universities, etc., and more generally organizations involved in astronomy and space sciences.

But many other related types of entries have also been included such as academies, advisory and expert committees, bibliographical services, data and documentation centres, dealers, distributors, funding agencies and organizations, journals, manufacturers, meteorological services, museums, norms and standards offices, planetariums, private consultants, public observatories, publishers, research institutions in related fields, software producers and distributors, and so on. Besides astronomy and related space sciences, other fields are also covered when justified (see the previous papers). All the categories have been appropriately flagged in a way that turned out to be very useful to shape up the samples as needed for the current study.

It is appropriate to remind here that we are dealing with validated and authenticated information (from signed and documented questionnaires), systematically compiled and presented, with a permanent updating-process scheme. The expertise built up over now almost a quarter of a century in this exercise, as well as the overall stability of the master files, guarantee an excellent exhaustivity of the entries and an homogeneous coverage of the practical data gathered together.

The files used are certainly the best sources available today for the study at hand. It should be recalled here that, contrary to most on-line resources, StarWorlds is not only WWW-oriented, but includes also all the organizations not yet on the web.

The study is based on the foundation years registered by the organizations in the databases mentioned above. Therefore it should be kept in mind that we are not investigating the foundation pattern of astronomy-related organizations over the past centuries, but the age of the organizations still existing and active nowadays.