In the solar atmosphere, thermal non-equilibrium (TNE) is a global thermodynamical state of atmospheric structures that is set by specific heating conditions - a stratified and quasi-steady heating.
TNE is commonly observed in active region coronal loops. It manifests as evaporation-condensation cycles that will show up as long-period intensity pulsations in coronal channels and as coronal rain showers in transition region/chromospheric emission.
 
Coronal rain has also been reported in topologies involving open-field, such as coronal null-points. However, the exact relationship of these events with TNE remains to be investigated. In particular, the periodicity of their cycles, if any.
 
In our study, we report the detection of combined long-period EUV pulsations and coronal rain events in open-close boundaries observed off limb with SDO/AIA. We analyze the thermal properties of these events to confirm these are indeed TNE events.
These observations lead to many questions on the interplay of TNE with interchange reconnection at coronal null-points and draw interesting perspectives on linking mass and energy transport in the solar atmosphere to solar wind release mechanisms.