From bright points to chromospheric fibrils (6/7)

Swedish 1-m Solar Telescope                                                          

Here we see how the Sun looks throughout the lower solar atmosphere. Each image shows a different layer. In the bottom most layer one sees bubble-like features that are the boiling from convection, transporting heat to the surface of the Sun from deep within. It is surrounded by darker spots which are colder as the pressure from magnetic fields inhibits such boiling. Small bright features are where smaller field concentrations make the plasma less dense, enough to let us see deeper into the Sun and thus into hotter layers. For the top most layer one sees a beautiful canopy of fibrils. At this height the magnetic field completely dominates over convection and thus one sees the magnetic field lines as they connect opposite polarities in the Sun. Scientists are interested in these arcades and other more open magnetic fibrils as they seek to understand, among other things, their role in heating the upper layers of the Sun.

The observations were taken with a tiltable interference filter at the Swedish 1-m Solar Telescope to sample the blue wing of the Ca II H line at 3967 Å. The images show the same field of view taken at different wavelengths, which is equivalent to sampling different heights in the solar atmosphere.

Image credit: Vasco Henriques (ISP/Stockholm)