Direct confirmation of two pattern speeds in the double-barred galaxy NGC 2950

We present the surface photometry and stellar kinematics of NGC 2950, which is a nearby and undisturbed SB0 galaxy hosting two nested stellar bars. We use the Tremaine-Weinberg method to measure the pattern speed of the primary bar. This also permits us to establish directly and for the first time that the two nested bars are rotating with different pattern speeds and, in particular, that the rotation frequency of the secondary bar is higher than that of the primary one.