Metis is the coronagraph of the scientific payload of Solar Orbiter, an ESA-NASA mission which aims to study the circumsolar region and the Sun poles. Metis data and operations are managed via the Metis Operations Facility (MOF), which is built, executed and maintained by ALTEC in collaboration with INAF, funded by Italian Space Agency. The collection of functionalities and subsystems within...
Coronal structures observed in visible light by coronagraphs are projected onto the plane of the sky due to the optically thin nature of the solar corona. Ray-tracing simulations of Thomson-scattered visible light therefore represent a powerful tool for interpreting how three-dimensional coronal features appear in coronagraphic images. In addition, the observer’s vantage point plays a crucial...
Various models exist to determine the electron temperature profile Te(r) in the solar corona, which is a key parameter for understanding coronal heating and solar-wind acceleration. Among these, the recent hydrodynamic equilibrium (DYN) method, introduced by Lemaire and Stegen (2016) and Lemaire and Katsiyannis (2021), links the coronal temperature to the radial evolution of electron density...
Abstract: Jets are collimated plasma eruptions found on the solar surface having sizes from few arcseconds to a fraction of the solar radius. We study cases of solar jets observed with Metis coronagraph on Solar Orbiter (SO), in combination with imagers as AIA on SDO or EUI on SO along with other coronagraphs such as LASCO/C2 on SOHO and COR2 on STEREO-A.
We characterize the jets geometry...
Observing eruptive prominences and other coronal structures,
Metis provides the intenzity maps in the hydrogen Lyman-alpha
line. Based on theoretical models of the Lyman-alpha formation,
we demonstrate a close correlation between the integrated line
intensity and plasma emission measure where the latter depends on
the effective thickness of the considered structure and its
electron...
The physical mechanism responsible for the generation and propagation of quasi-periodic fast-propagating (QFP) magnetosonic wave trains in the solar corona remains poorly understood. While several events have been analyzed and modeled via numerical simulations, key questions regarding their origin and evolution remain open. We present a preliminary analysis of a coronal event occurred on 5...
The solar wind is an uninterrupted flow of highly ionised plasma that streams from compact sources at or near the Sun and expands into the whole interplanetary space, being a major driver of space weather phenomena. Understanding the conditions that regulate the formation of the solar wind, its acceleration across the corona, and its transition to the heliospheric propagation regime is key...
The solar wind plays a central role in shaping the heliosphere and driving space weather, though the details of its origin and acceleration are full not fully understood. A major challenge lies in obtaining global measurements of the solar wind speed in the acceleration region, where remote-sensing techniques and indirect determinations are required. The Metis coronagraph on board the Solar...
The quadrature and corotation configurations between Parker Solar Probe (PSP) and Solar Orbiter (SolO) provide an exceptional opportunity to study the coupling between the solar corona and the nascent solar wind. We analyze coordinated remote-sensing (RS) and in-situ observations obtained during periods when PSP corotated with the Sun while SolO viewed the same source regions from...
Decades of density measurements made throughout the inner heliosphere show that the solar wind is often comprised of mesoscale structures. One type of mesoscale solar wind structure manifests as periodic trains of density enhancements, with scales of 0.2 mHz (~90 minutes) to 5 mHz (~ a few minutes). Periodic density structures directly drive oscillations in Earth’s magnetosphere as a...
The backbone of Solar Orbiter coordinated observations is constituted by the so-called SOOPs (Solar Orbiter Observing Programs), which are designed to address specific science objectives of the mission.
This contribution focuses on the SOOP identified as "R_FULL_HRES_HCAD_Density-Fluctuations", which has the primary objective of studying density fluctuations in the middle or extended corona....
Magnetohydrodynamic (MHD) waves are ubiquitous in the solar atmosphere and are key in many models for seismological or energy conversion processes. Metis has observed such waves too thanks to its unprecendented cadence. Using MHD simulations, we study wave propagation in a helmet streamer. Our model includes important physics such as spherical expansion, gravitational stratification, thermal...
The METIS Coronagraph onboard Solar Orbiter observes simultaneously in Visible (VL) band between 580 and 640 nm and Ultraviolet (UV) band at 121.6 nm. It observes at a high spatial and temporal resolution, thus, allowing a comprehensive analysis of solar events.
In particular, the Metis team is creating a database of solar eruptive events observed in both the VL and UV channels. The CME...
A key challenge for maximising Solar Orbiter science return is building an interoperable Python ecosystem for working with mission data, enabling rapid and reliable connections between observations from different instruments. Cross-instrument event catalogues are central to this, but creating catalogues that are accurate and usable by the wider community requires consistent event definitions,...
Data provided by the instruments placed on board Solar Orbiter are pivotal for several different, yet intertwined, applications. For instance, observations from the EPD/HET instrument are needed to run Monte Carlo simulations to reproduce the tracks in the Metis cosmic-ray matrices and for comparison with results of the visual analysis.
To make visual analysis tasks easier and faster, our...
Understanding how erupting prominences evolve as they rise through the middle corona is essential for constraining the early phases of coronal mass ejections (CMEs).
This study aims to investigate the evolution of erupting prominences across the transition from the inner to the middle corona by combining observations from EUI/FSI and Metis aboard Solar Orbiter. The unprecedented...
Studying the evolution of the energy budget involved in solar eruptions is central, particularly to understanding their early stages, but also for the subsequent interplanetary expansion. For this purpose, it is important to quantify the thermal energy evolution of erupting plasma, compare it with the expected adiabatic cooling, and determine at least approximately how energy is partitioned...
As Coronal Mass Ejections (CMEs) propagate through the corona, they should cool adiabatically as an almost isolated plasma bubble, yet observations indicate that heating processes can offset this cooling and keep temperatures nearly constant (Sheoran 2023) or increasing (Bemporad et al. 2007; Bemporad 2022). Although several heating mechanisms have been proposed for individual events (e.g....
While asymmetric eruptions and nonradial propagation of solar filaments are typically attributed to inhomogeneous overlying magnetic fields, the role of the filaments’ intrinsic asymmetry remains underexplored. In this work, we analyze the evolution of an intermediate-type filament from its activation and asymmetric eruption to its propagation alongside an associated coronal mass ejection...
The Earth-orbiting ASPIICS/Proba-3 and the Sun-orbiting Metis/Solar Orbiter provide a changing, multi-point view of the solar corona, depending on the relative Earth-to-Solar Orbiter positions on- and out-of-the-ecliptic plane. The first Metis-ASPIICS coordinated observations took place in 2025, during the Solar Orbiter superior conjunction in August, its quadrature in September and inferior...
We have analyzed high temporal frequency visible light observations acquired by Metis coronagraph on Solar Orbiter during the perihelia on October 2022, April 2023 and September 2024.
In particular, we focused on series of total and polarized Brightness observations lasting for 40 min up to few hours, acquired with a cadence of 20 s and 60 s. The field of view of the observations ranges from...
Metis, the coronagraph on board Solar Orbiter, is an externally occulted instrument with a field of view (FOV) spanning 1.7°–3.4°, which, over the course of a typical spacecraft orbit, corresponds to heliocentric distances from 1.7 to about 10 solar radii. Metis operates with two radiometric channels: one measures coronal emission in a narrow ultraviolet (UV) band centered on the H I Lyman-α...
In addition to the polarised and unpolarised wideband filters (white light continuum), The PROBA-3/ASPIICS coronagraph has two narrowband filters (NBF) centered on specific spectral lines: Fe XIV (530.45 nm; FWHM 0.5 nm; imaging the corona around 1.5-2 MK) and He I D3 (587.72 nm; FWHM 2 nm; imaging prominences). Because the wideband filter is quasi-free of any coronal emission line, it is...
ASPIICS is a 144m baseline coronagraph onboard the Proba-3 mission, designed to perform regular observations of the solar corona in visible light over a field of view (FOV) from 1.1 to 3$R_{Sun}$. Despite very low minimal FOV, the amount of the diffracted light reaching the ASPIICS detector is extremely small and is not detectable in routine coronal images. However, this diffracted light...
Metis was designed to capture images of the Solar Corona in visible (VL, 580-640 nm) and ultraviolet (UV, Ly-alpha, 121.6 nm) wavelengths. This work focuses on a preliminary characterization of the instrument's optical performance in the UV channel through Point Spread Function (PSF) analysis.
Our approach involves the study of stellar sources detected in the Metis UV Field of View (FOV)....
