Catalogue of Intrinsic Colours of Stars in the Ultraviolet.

S2/68 sky survey telescope observations have allowed the derivation of 25 intrinsic UV colors for normal stars covering most spectral types and luminosity classes between O6.5 V and K3 III. The 25 colors are based on absolute fluxes covering the 1400-2740 A wavelength range, and have been corrected from the absolute calibration of S2/68 to the standard calibration of Bohlin et al. (1980) for the star Eta UMa. The local interstellar extinction curve has been reexamined, using 1200 stars of spectral type B5 and earlier, and the mean values of A(lambda)/E(B-V) are calculated for all passbands. These values are found to be in good agreement with previous determinations, and no significant variations from the mean curve are found to occur with either galactic direction or wavelength.