Magnitudes, colours and coordinates of 175 ultraviolet excess objects in the field 13h +36 .

Here reported are the positions and magnitudes ili a four colour (`&,b, V, i) system of 175 ultraviolet excess objects down to b = 19.5 ili a 60 >c 60 degree field centered at 13h, +360. Most of these objects appear to be Q.S.O.'s (Braccesi and Formiggini, 1969). The paper is divided in two sections: the first gives an exhaustive description of the photometric system employed and how it has been calibrated against the classical U, B, V system. The second section describes the catalogue itself. Key words: cosmology - quasi-stellar objects - multicolour photometry - infrared excess