ANTI-STURMIAN SLOW DISCRETE MODES MODELING LONG PERIOD LOOP PROMINENCE OSCILLATIONS

The slow magnetosonic waves can, under certain conditions, have a discrete set of regular eigenmodes similar to the discrete Alfven wave spectrum (Sturmian or anti-Sturmian). The latter were shown to explain the short period (2-8 min) prominence loop oscillations as a global Alfven modes. Here, we slow that the anti-sturmian discrete slow wave spectrum can explain the long period (24-84 min) oscillations of solar loop prominences. We have also estimated the Q (Q−1 = Imω/ω) factor, due to electron and ion Cherenkov damping, for the loop cavity, and found the value of Q ~ 6 which is compatible with the observations of loop period oscillation and life time.