For this work, four fields have been observed in Bessel V and Gunn I with the 1.54 m Danish telescope at the European Southern Observatory (ESO), La Silla (Chile) on February , 1997 (camera C1W11/4 with 2k2k pixels and a nominal field of view of ). The coordinates of the fields, the number of averaged exposures, and the total exposure time per filter are given in Table 1.
Table 1. General information on the fields: central coordinates, number of exposures and integrated exposure time for both filters, dimension of the selected part of the field (see text for details), and total number of stars therein.
The fields have been chosen on the large scale surface photometry maps of the Milky Way (Hoffmann et al., 1998 and Kimeswenger et al., 1993) and corresponding term maps which display all points of the Milky Way having the same colour (Schlosser et al., 1995). These maps show large scale structures and are therefore suitable for the selection of interesting areas. The integrated colours of the fields we select show they are affected by low interstellar absorption. Two of the fields point in the direction of the Sgr-Car arm and their integrated UBVR colors are consistent with the presence of a significantly fraction young population. In Fig. 1, the positions of the observed fields are plotted over the relevant part of the Galactic V map.
© European Southern Observatory (ESO) 2000
Online publication: September 5, 2000