Observation of an Instability in a 'Quiescent' Prominence
  We present the detection of a bubble-like cavity traveling through a quiescent prominence. The H-alpha emission in the cavity is >16 times smaller than in its surroundings. The cavity propagates almost with the phase-velocity of MHD compressive waves. We suggest a disruption of the lateral magnetic stability. The Ca II 8542 spectra indicate a material outflow along the lines of force up to 12 km/s. 
G. Stellmacher and E. Wiehr
astro-ph.SR physics.plasm-ph