Revisiting the cycle-rotation connection for late-type stars

We analyse the relation between activity cycle length and Rossby number collected a sample of 44 main sequence stars with well-known periods rotation periods. find linear behaviour in double-logarithmic period. The bifurcation into long short period branch is clearly real but it depends, empirically, on colour index B-V, indicating physical dependence effective temperature position sequence. Furthermore, there also correlation convective turnover time relative depth convection zone. Based this, we derive empirical relations number, for relations, estimate scatter deviation 14% 28% long-period branch. With these obtain good match 10.3 yr well known 11-year solar Schwabe value 104 Gleissberg Sun. Finally, suggest that cycles short-period appear to be generated deeper layers zone, while seem related fewer deep show broader B-V range, more suitable parameter universal cycle-rotation than just alone. As proof, demonstrate our stellar are consistent cycle, contrast earlier studies using their relations. Previous have tried explain Sun presentation via other kinds dynamo, however, study, no evidence found would another type dynamo stars.