Magnetic Tendrils The magnetic fields of a pair of active regions are seen connected to each other over hundreds of thousands of miles in this video clip (Mar. 14-16, 2012). Like thin, twisted vines the field lines from each stretched out above the Sun and established a link with the other. Charged particles are spinning along the field lines making the lines visible in extreme ultraviolet light. The material being observed here is ionized iron heated to over a million degrees (171 Angstrom wavelength). Looping arcs of field lines can also be seen above each of the active regions, often the sources of solar storms.