Interstellar extinction and galactic structure

Colour excesses and photometric distances of open clusters compiled by Janes & Adler and Lyngå have been used to study the distribution of interstellar matter within a few kiloparsecs of the Sun. In general the reddening material is highly concentrated near the galactic plane. It is found that the plane defined by the distribution of interstellar matter is inclined to the formal galactic plane by an angle of |$0_{.}^{\circ}8\pm0_{.}^{\circ}2$| and shows a maximum upward tilt towards l~60°. The scale height of the reddening material is found to be 0.16±0.02 kpc. Based on the distribution of whole interstellar matter, the Sun is found to be situated at a distance of about 10 pc above the galactic plane of symmetry defined by the reddening material, while from a subsample in the direction of maximum tilt this figure is found to be 3±4 pc.