The solar corona has been investigated in the last decades through observations coming from several spacecraft. The Metis coronagraph, aboard the ongoing Solar Orbiter mission, extends the UVCS/SOHO spectrocoronagraph observations of the scattered ultraviolet emission of the coronal plasma performed during solar activity cycle 23, by simultaneously imaging the coronal visible light polarized brightness (VL pB), in the spectral bandpass 580-640 nm, and the coronal ultraviolet H I Lyα emission, in the spectral window 121.6 ± 10 nm. We present here some specific observations, such as those taken on May 15, 2020, from which detailed information about the coronal outward velocity were inferred by applying the Doppler dimming technique. Read more at https://espos.stream/2023/03/30/Capuano/.

New instrumental and telescopes covering the optical and UV spectral regions have revealed a range of small-scale dynamic features, many of which may be related. Direct observational evidence in terms of tracking spicules across multiple wavelengths is needed to understand their role in heating the solar atmosphere. This study uses the Hα filtergrams obtained by the CRISP on SST and co-aligned IRIS data to study the signature of the Rapid Blue-shifted Excursions (RBEs) in the transition region. By studying the spatio-temporal evolution of RBEs in Hα and SJI 1400 Å channels, we found that ∼53 % of the RBEs have a transition region counterpart. From the RBE-like events that have a Si iv 1394 Å line profile, 78% of them show a Si iv line flux increase. The events that show line flux enhanceme

Susanna Parenti, Karine Bocchialini

The solar corona temperature is maintained to more than 1 MK. One of the main theories of the coronal formation (Parker 1988) suggests that the energy is dissipated into the corona through a high number of impulsive, low energy (10²⁴ ergs) heating events, called “nanoflares”. On 30 May 2020, during its first high temporal and spatial resolutions observations, 1463 small (400 – 4000 km) and short lived (10-100 s) EUV brightenings were detected in the Quiet Sun by the high resolution UV imager HRI-EUV (174 Å) on board Solar Orbiter. These may be the signatures of nanoflare heating. As HRI-EUV is sensitive to both coronal and transition region emission, our goal is to verify if these brightenings indeed do reach coronal temperatures. As spectroscopic data were not available during the 2020 Ma

The phase mixing of Alfvén waves is one of the most promising mechanisms for the heating of the solar atmosphere. The damping of waves in this case requires small transversal scales, relative to the magnetic field direction; this requirement is achieved by considering a transversal inhomogeneity in the equilibrium plasma density profile. Using a single-fluid approximation of a partially ionized chromospheric plasma, we study the effectiveness of the damping of phase-mixed shear Alfvén waves and investigate the effect of varying the ionization degree on the dissipation of waves. Read more at https://espos.stream/2024/01/25/Mcmurdo/.