An extensive series of arcs, observed in profile, can be seen making a long distance connection between two active regions (Mar. 15-17, 2011). As SDO observed in extreme ultraviolet light, a series of magnetic field lines generated a well-defined pathway from one bright active region back to another that rotates into view. Active regions, which are magnetically intense areas, appear as sunspots if viewed in normal filtered light. By rough estimate that reach extends about 250,000 miles, about the distance from the Earth to the Moon.
Credit: SDO, Steele Hill, http://www.helioviewer.org