Abstract
We have determined radial velocities by photographic Fabry-Perot interferometry, at 236 points in and around the small (1 X 3 arcmin) bipolar H II region Sharpless 106. The average velocity of the brighter lobe is blue shifted by 5 km s-1 with respect to the fainter surroundings. This probably indicates that one is observing the front side of an expanding thick shell with high internal opacity. It is pointed out that radial velocities from radio frequencies show two peaks displaced by 4 km s-1 This is consistent with the fact that the object is associated with a molecular, in particular a CO cloud, which may also be expanding. A kinematic distance at the longitude of S106 (7406) will not be too reliable. We argue that if any, it will be more reliable if estimated from radio data. We believe the distance of S106 to be less than 1 kpc, more nearly 600 pc, in agreement with the suggestion of Eiroa et al. (1979) based on physical arguments on the ionization source of 5106.
