High resolution observations of interstellar Na I towards HD 174632

High-resolution observations of interstellar Na I towards the relatively nearby (180 pc) and lightly reddened, [E(B−V)=0.12] B8V star HD 174632 are presented. There are two distinct interstellar cloud components in this line-of-sight, with heliocentric velocities of about −4.4 and −17.6 km s−1. A third, much weaker, component at about −21.7 km s−1 also appears to be present. Na I column densities for these components have been obtained by line-profile fitting, and estimates have been made of the N(Na I)/N(H) ratios. These are found to be consistent with standard diffuse interstellar clouds. Arguments are presented that these clouds are associated with the boundary between the local low-density interstellar bubble and the neighboring Loop I bubble, at a distance between about 50 and 100 pc from the Sun