First Metis Detection of the Helium D3 Line Polarization in a Large Eruptive Prominence

0580065 - ASÚ 2024 RIV US eng J - Journal Article
Heinzel, Petr - Jejčič, Sonja - Štěpán, Jiří - Berlicki, Arkadiusz … Total 27 authors
First Metis Detection of the Helium D3 Line Polarization in a Large Eruptive Prominence.
Astrophysical Journal Letters. Roč. 957, č. 1 (2023), č. článku L10. ISSN 2041-8205. E-ISSN 2041-8213
R&D Projects: GA ČR(CZ) GA22-34841S
Institutional support: RVO:67985815
Keywords : solar prominences * coronagraphic imaging * solar corona
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 7.9, year: 2022
Method of publishing: Open access

Metis on board Solar Orbiter is the space coronagraph developed by an Italian-German-Czech consortium. It is capable of observing solar corona and various coronal structures in the visible-light (VL) and UV (hydrogen Lyα) channels simultaneously for the first time. Here we present observations of a large eruptive prominence on 2021 April 25-26, in the VL, taken during the mission cruise phase, and demonstrate that apart from the broadband continuum emission, which is due to the Thomson scattering on prominence electrons, we detect a significant radiation in the neutral-helium D3 line (587.6 nm), which lies within the Metis VL passband. We show how the prominence looks like in Stokes I, Q, and U. We consider two extreme cases of the prominence magnetic field, and we separate the Stokes I and Q signals pertinent to Thomson scattering and to the D3 line. The degree of linear polarization of the D3 line (both Q and U) indicates the presence of the prominence magnetic field, hence Metis can serve as a magnetograph for eruptive prominences located high in the corona.
Permanent Link: https://hdl.handle.net/11104/0348842