Magnetohydrodynamic waves in a solar prominence

The presence of oscillations in solar prominences has been known for a long time, and at first they were thought to be initiated by shock waves emitted by a flare. However, short- and long-period oscillations, not related to flares, have been abundantly reported during recent years. In limb prominences they have been detected mainly in the velocity field, whereas in filaments they are hardly detected at all. In this paper we try to provide a theoretical explanation for these oscillations by investigating the magneto-acoustic-gravity modes of vibration of a Kippenhahn-Schlueter prominence model. First of all, we obtain the magneto-acoustic modes for a very thin prominence with horizontal magnetic field, and later we solve the full problem numerically. Our results suggest that short-period oscillations detected in limb prominences could be due to the fundamental and first harmonic of the magneto-acoustic-gravity slow modes of the prominence itself, while the long-period oscillations could be due to global oscillations of the whole surrounding arcade.