2 Observations

The data were collected during two runs in 1997: the first in April ( $\rm 11^{th}-15^{th}$) and the second in December ( $\rm 23^{rd}, 24^{th}$ and $\rm 26^{th}$). All nights of the first run and the first two of the second run were photometric and had a stable seeing.

Observations were done with the ESO 91 cm DUTCH telescope, at La Silla (Chile). The same same CCD$\char93 33$ was used in both runs, a thinned CCD with $512\times512$ pixels, each projecting $0\hbox{$.\mkern-4mu^\prime$ }442$ on the sky, with a total field of view of $3.77\times3.77 (\hbox{$^\prime$ })^2$, and the same set of V Johnson and i Gunn filters.

Two short (10-45 s), one medium (90-120 s) and one long (600-1800 s) exposures were taken in each band (depending on the cluster distance modulus) for one to three fields (in order to ensure a statistically significant sample of stars) for each of the proposed objects. Also a large number of Landolt ([1992]) standard stars were measured during each night.

In Table 1 the 39 observed GGCs are presented. Column 1 gives an identification number adopted in this paper; cluster NGC numbers and alternative names are given in Cols. 2 and 3. The observing dates are in Col. 4, the number of covered fields in Col. 5, the mean seeing for each filter in Col. 6, and the integration time for the long exposures in Col. 7. In Fig. 1 we show the heliocentric distribution of the clusters of our entire catalog.