Eventi

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 polarised 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. Here some specific observations are shown, such as those taken on May 15, 2020, from which important results about the solar wind outflow velocity were inferred by applying the Doppler dimming technique. Other results on the coronal solar wind velocity are presented, obtained by considering the data acquired during the first quadrature of the Solar Orbiter and the Parker Solar Probe (PSP) spacecraft with respect to the Sun. In particular, the same parcel of plasma on the East limb was remotely observed with Metis between 3.5 R⊙ and 6.3 R⊙ on January 17, 2021, during low-cadence synoptic mode observations, and was sampled in situ by PSP at about 22 R⊙ on January 18, 2021. In this case, information about several coronal parameters were inferred with unprecedented details, thanks to the high quality of Metis and PSP data. Finally, other results concerning the first coronal mass ejection observed with Metis on January 16-17, 2021 are reported. In this case, also considering data coming from instruments onboard Solar Orbiter and other spacecraft, a 3D reconstruction and detailed physical information about this structure were obtained. Therefore, Metis, even when operates in synoptic mode and in synergistic coupling with other instruments, allows to get novel and detailed information about the structure of the solar corona with an accuracy never reached until now.