A KINEMATICALLY DERIVED INTERSTELLAR EXTINCTION IN THE GALACTIC MIDPLANE OF THE GREATER SOLAR NEIGHBORHOOD

A total interstellar extinction in the B and V bandpasses is derived f rom the difference between the photometric and kinematic distances of a set of 2.3 X 10(5) stars in a galactic layer of 300 pc halfwidth and up to a distance of 600 pc from the Sun. A mean reddening is derived over the galactic midplane and a continuous region similar to that of the Lindblad Ring is delineated by a color excess of 0.11 mag. Rough v alues of 180 pc for the scale height, an internal velocity dispersion of 7 +/- 1 km s-1 a surface density of 3 +/- 2 M. pc-2 and a variation in the potential depth of +/- 4 X 10(6) M. are derived from the diffe rence between the inner and outer regions of the Lindblad Ring.