In many field of the modern astronomy the coordination of observational programmes becomes more and more important since the main difficulty in the full understanding of a physical phenomenon is often the discrete sampling of the signal or the large gaps in the time distribution. For these reasons the astronomical community deserves an increasing attention to the organization of multisite projects (campaigns, long term surveys, simultaneous observations from earth and space, ... ). A large number of examples can be found in Jaschek & Sterken (1988).
There is an obvious condition to satisfy for a multisite project: a large number of available telescopes well spread in longitude. In the current development of the astronomical techniques there is a great attention to automatic telescopes and maybe in the future the existence of a network will ensure the continuous acquisition of a large amount of data without the presence of the man within several hundred of kilometers. It will be a great day for astronomy (and much greater for the astronomers, too), but such a future should be prepared using the large amount of experience gained from similar projects carried out with observers present at the telescope. If we look at the situation of observing sites around the world we notice that well organized multisite campaigns can already reach the important target of a 24 hours continuous monitoring.
To maintain this facility, a sufficient number of telescopes with a flexible schedule permitting the allocation of long observing runs should be available. If we consider the guidelines of the instrumentation development in these years, the small telescopes are the obvious answer to this request, since large telescopes are devoted to use sophisticated and advanced instruments, which, in general, differ from observatory to observatory and hence are not suitable to obtain the homogenous data necessary for a multisite survey. Moreover, the increasing efficiency of solid-state detectors makes faint stars accessible also to small apertures. Both low costs and high performances of small telescopes are facts well established in the management of instrumentation resources (Warner 1986).
In such a context, the importance of small telescopes should not be questioned, but in practice often the discussion moves from the ground of the scientific results to that of scientific policy, passing through financial considerations. The problem is very serious, as it is demonstrated by the progressive disappearance of telescopes from Western Europe, and attention to this should be paid by small telescope users. Of course, the closing of an observatory is also a direct consequence of the site condition degradation because of the increasing urbanization and it should be recognized that astronomy alone cannot oppose solid arguments concerning the social reasons responsible for this process. However, initiatives should be taken to safeguard the scientific possibilities offered by an observatory easily accessible from local institutions and to show the real loss of scientific potential caused by such a closing. Therefore, the variable star observers should not miss the opportunity to always draw attention on the importance of a continuous monitoring of an object, because I feel that in the astronomical literature the time resolution is not considered a facility as important as, for example, spatial resolution. On our own side, we particularly stress the importance of the survey of a d Scuti star for 2 - 3 months, as it is possible at Merate Observatory (see in Poretti & Mantegazza 1992 the concerning references), a typical "urbanized" site, even if located in the North Adda Park. In particular we are trying to preserve it from light pollution, since financial limitations are not a major problem (at least at the moment).
The worldwide announcement of a planned observing campaign is not a simple task. Many different ways to inform the astronomical community are used and maybe the fastest way is to use the Information Bulletin on Variable Stars (IBVS), a publication well known to all variable star observers (see Szabados' specification in Jaschek & Sterken 1988, p. 13).
Therefore, the use of IBVS is strongly encouraged. However, campaign organizers generally prefer to contact potential participants by mail, e-mail, other bulletins,... This practice has the undoubted advantage to ensure some participation and should be encouraged, but even here the IBVS can be used to announce the campaign.
If the announcements are made sufficiently in advance, then time allocation at ESO and/or USA telescopes can be requested to ensure both a better 24-hours coverage and a longer duration of the campaign. The organization of multisite campaigns will contribute to emphasize the importance of small telescopes, overall the local ones. For this reason the Editorial Committee of this Newsletter strongly encouraged these projects. Indeed, the Delta Scuti Newsletter was created in part with the aim to contribute to the organization of such campaignes. In spite of possible delays caused by the publication dates, it can play the important role of providing list of potential observers and available telescopes.
The requested information should be sent (deadline September 30, 1993) to Jaschek C., Sterken C., 1988, Coordination of Observational Projects in Astronomy, Proc. of a Conference held in Strasbourg, November 23-26, 1987, Cambridge Univ. Press
sperl@astro.ast.univie.ac.at