Observations of Mini Coronal Dimmings Caused by Small-scale Eruptions in the Quiet Sun

Abstract

Small-scale eruptions could play an important role in coronal heating, generation of solar energetic particles (SEPs), and mass source of the solar wind. However, they are poorly observed, and their characteristics, distributions, and origins remain unclear. Here a mini coronal dimming was captured by the recently launched Solar Orbiter spacecraft. The observations indicate that a minifilament eruption results in the dimming and takes away approximately (1.65 ± 0.54) × 10 ^13 g of mass, which also exhibits similar features as the sources of SEP events. The released magnetic free energy is of the order of ∼10 ^27 erg. Our results suggest that weak constraining force makes the flux rope associated with the minifilament easily enter a torus-unstable domain. We discuss that weak magnetic constraints from low-altitude background fields may be a general condition for the quiet-Sun eruptions, which provide a possible mechanism for the transport of coronal material and energy from the lower to the middle or even higher corona.

Keywords

• Quiet sun
• Solar coronal transients
• Solar magnetic fields
• Solar filaments