Absolute ultraviolet spectrophotometry from the TD 1 satellite. II. Observations of B star continua shortward of 2500 Å.

Summary. The slope of the continuous energy distribution determined from 1800 A to 2500 A on calibrated S2/S68 spectrophotometric tracings is well correlated with the spectral type and the B - V color index of 80 bright B stars. A flux ratio defined with respect to such a slope is then considered to be a measurable characteristic of each spectral type along the sequence B 0 to B 9.5. The absolute level of the Balmer continuum is described in terms of an index representing the UV excess (or deficiency) of the stellar continuous flux at 2100 A with respect to a model for Vega. Key words: ultraviolet spectrophotometry - B stars - stellar continuum