Observing the solar corona from a formation-flying mission. First results of Proba-3/ASPIICS

TL;DR

This paper presents initial observations of the solar corona using the Proba-3/ASPIICS formation-flying coronagraph, revealing detailed structures and dynamic phenomena at unprecedented spatial and temporal resolutions.

Contribution

It introduces a novel formation-flying coronagraph setup that enables eclipse-like coronal observations close to the solar limb with low straylight, capturing small-scale outflows and inflows.

Findings

First high-resolution observations of small-scale coronal outflows and inflows.

Detection of dynamic phenomena like eruptions, jets, and CMEs.

Expanded understanding of the scales involved in slow solar wind formation.

Abstract

We report the first results from observations of the solar corona by the ASPIICS coronagraph aboard the Proba-3 mission. ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun) is a giant coronagraph consisting of the telescope mounted aboard one of the mission's spacecraft and the external occulter placed on the second spacecraft. The two spacecraft separated by around 144 m fly in a precise formation up to 5.5 hours at a time, which allows coronal observations in eclipse-like conditions, i.e. close to the limb (typically down to 1.099 Rs, occasionally down to 1.05 Rs) and with very low straylight. ASPIICS observes quasi-stationary structures, such as coronal loops, streamers, quiescent prominences, and a variety of dynamic phenomena: erupting prominences, coronal mass ejections, jets, slow solar wind outflows, coronal inflows. In particular, weak, widespread and persistent small-scale outflows and inflows between 1.3 and 3 Rs are observed at a high spatial (5.6 arcsec) and temporal (30 s) resolution for the first time, expanding the range of scales at which the variable slow solar wind is observed to form.