Abstract
The steady flow pattern around a wind-producing star immersed in an interstellar disk-shaped cloud is analyzed. The wind is taken as isotropic. In particular, we apply the model to an infinite, isothermal and self-gravitating disk. The radial velocity of the emitting material is also presented. The model is found to account `satisfactorily for the observed shapes of optical Bipolar Nebulae; especially for the acute tips which can be seen in several of them. Further, it is concluded that such acute tips represent the hallsnark of wind-produced nebulae.
