Solar corona diagnostics with Metis observations

Giuseppe Capuano

Hosted by University of Catania, Italy on March 30, 2023


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. Other results on the coronal solar wind outflow velocity were obtained by considering the quadrature of Solar Orbiter and PSP with respect to the Sun, when the same parcel of plasma was observed remotely with Metis between 3.5 R and 6.3 R on January 17, 2021, on the East limb and in situ by PSP at about 22 R on January 18, 2021. In this case, information on several coronal parameters were obtained with unprecedented details, thanks to the high quality of Metis and PSP data. Finally, other results concern the first CME observed with Metis on January 16-17, 2021, during low-cadence synoptic mode observations. In this case, also considering data coming from instruments onboard other spacecraft and on Solar Orbiter, a 3D reconstruction and physical information of 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 on the structure of the solar corona with an accuracy never reached until now.

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