Abstract
The significance of recent improvements made in the absolute monochromatic flux measurements of the Sun and Vega are discussed with a special emphasis on the absolute calibration of the V-magnitude of stars. The difficulties relating to the determination of vacuum ultraviolet fluxes are outlined and the improvements that can be achieved using synchroton radiation as the fundamental laboratory source are presented. Colour indices derived from OAO-2 observation are given for about 80 early type stars and the (1700 – V) colour is discussed in terms of interstellar reddening and sensitivity to effective temperature. Basic problems requiring further investigation are finally outlined.
Publisher
Cambridge University Press (CUP)