The Bimodal Corona Revisited

During solar cycle 24 the Sun exhibited a sharp turn-on of coronalactivity in Feb-March 2011. This took the form of a sudden increase inthe coronal emission in lines formed at temperatures of around 2 MK orhotter, relative to lines formed at temperatures of 1 MK or cooler. Thisphenomenon suggested that the corona is a 2-state system with behaviorformally different at solar maximum compared to solar minimum.In this paper we investigate whether this phenomenon is recurrent andsearch for a similar sharp turn-on in cycle 25.