Reference stars for 12 low-extinction fields

The first column of the catalog indicates the star label, formed by a number that designates the window (see Table 1) and a sequential counter. The following columns contain the mean right ascension, the corresponding standard deviation (in seconds); the mean declination, its standard deviation (in arcseconds) (J2000); the weighted average magnitude, its standard deviation and weighted error.

Stars belonging to the Tycho Catalogue are indicated with a "T" in the second column. We stress that, being a natural extension of the Tycho Catalogue, the Valinhos Reference Catalogue is not complete up to the given magnitude in that regions, but instead constitute a reference set which may prove useful for dedicated studies of low-extinction fields (Dominici, 1998, MSc. Thesis IAG/USP).