Far Ultraviolet Spectroscopic Explorer observations of the HD molecule toward HD 73882

The Lyman and Werner band systems of deuterated molecular hydrogen (HD) occur in the far-UV range below 1120 Angstrom. The high sensitivity of the FUSE mission can give access, at moderate resolution, to hot stars shining through translucent clouds in the hope of observing molecular cores in which deuterium is essentially in the form of HD. Thus, the measurement of the HD/H(2) ratio may become a powerful new tool to evaluate the deuterium abundance, D/H, in the interstellar medium. We report on the detection of HD toward the high-extinction star HD 73882 (E(B-V) = 0.72). A preliminary analysis is presented.