Abstract
A simple geometrical model of a barred spiral with central nucleus is considered. The problem of rotation about an axis normal to the bar axis is discussed, and it is found that a certain density distribution in the bar will make the system remain stable for a time of order 3 × 10 9 years. When the ratio of the diameter of the nucleus to the total length of the bar is 1:3, as in Fig. 2, this situation requires the ratio of total bar mass to central mass to equal 0.54. If the latter is taken to be 5 × 10 10 ⊙ the period of rotation is 1.5 × 10 8 years.

This publication has 0 references indexed in Scilit: