Magneto-thermal convection in solar prominences

Plasma bubbles in the solar corona Recent observations of solar prominences with the optical telescope aboard the Hinode satellite have revealed dark, low-density bubbles that undergo Rayleigh–Taylor instabilities and evolve into dark plumes within coronal cavities — large, low-density regions formed by hemispheric-scale magnetic flux ropes in the outer solar atmosphere. New optical and extreme-ultraviolet data from Hinode and the recently launched NASA Solar Dynamics Observatory show that these prominence cavity structures are heated to temperatures of at least 250,000 K and perhaps as high as 106 K, which is 25–100 times hotter than the overlying prominence. These findings identify a source of buoyancy for these plasma bubbles and point to a previously unrecognized form of magneto-thermal convection in the outer solar atmosphere.