Coordinated coronagraphic observations from proba-3 and Aditya-L1: Investigating coronal mass ejection energetics in the inner corona

Abstract

Context. Constraining the plasma properties and energetics of coronal mass ejections (CMEs) in the inner corona is essential for understanding their early evolution, yet it remains challenging because of limited observations. Aims. We investigate the mass and density evolution as well as energy partitioning of two CMEs observed on 14 and 16 September 2025, and assess the potential of coordinated Proba-3/ASPIICS and Aditya-L1/VELC observations to constrain CME energetics in the low corona. Methods. We present the first coordinated observations of CMEs obtained simultaneously by Proba-3/ASPIICS and Aditya-L1/VELC. Using ASPIICS white-light observations, we estimated the CME mass, volume, number density, and the evolution of kinetic, thermal, and magnetic energies. Magnetic energies were estimated from observed CME properties using observationally constrained, physically motivated assumptions. Simultaneous VELC Fe XIV 5303 A observations provide independent estimates of the emission measure, electron number density, thermal energy, and CME lateral extent. Results. The electron number density evolves as ne χ r-33 for the 14 September CME and as ne ∝ r-6 for the 16 September CME. The two events exhibit markedly different energy partitioning in the low corona. For the 14 September CME, the kinetic and magnetic energies are comparable, while the thermal energy remains nearly two orders of magnitude smaller, indicating limited plasma heating. In contrast, the 16 September CME exhibits a substantial thermal-energy enhancement, with thermal energy eventually becoming comparable to kinetic energy. For both CMEs, the estimated magnetic energy remains comparable to or exceeds the kinetic energy over the observed height. Conclusions. Our results demonstrate the scientific potential of synergetic ASPIICS and VELC observations for constraining the CME mass, density, and energetics in the inner corona, providing new observational constraints on the early evolution of CMEs.