uvby-{beta} photometry of A and F southern stars

The present results, combined with those previously published for the Northern Hemisphere, complete the coverage of the spatial distribution of interstellar reddening in the entire solar neighborhood. The new reddening maps show that the interstellar matter within 300pc of the Sun forms a single very large cloud complex that is somewhat asymmetrical with respect to both the galactic center and the galactic plane.

This complex is characterized by pronounced local irregularities in both density and spatial extent. The observations further indicate that (1) the cloud complex is not associated with Gould's belt; (2) there exist large regions of the sky devoid of dust; (3) interstellar reddening is negligible at the galactic poles; (4) the role of intercloud dust in the Southern Hemisphere is minor although more important than in the Northern Hemisphere; (5) the Sun is not located in a dust-free, spherically symmetric bubble as previously thought; and (6) the Sun is, however, located in an elongated dust-free region known as the "local trough."