Velocity variability of semiregular and irregular variables

We compare velocities from near infrared lines with center- of- mass velocities for a sample of semiregular and irregular variables to search for indications for a convective blueshift. It is shown that a general blueshift is present but that the light variability is obviously not dominated by convective cells but rather by stellar pulsation. All stars of our sample show a similar shape and amplitude in the velocity variations. Long secondary periods are a common feature in these objects and strongly influence the measured velocity shifts. The star V366 Aql is found to be the first SRV showing line doubling.