Spectroscopic He I 1083 nm prominence eruption observations in the middle corona with MLSO/UCoMP

TL;DR

This study demonstrates the use of He I 1083 nm spectroscopic observations from UCoMP to detect and analyze prominence eruptions associated with CMEs, offering insights into their magnetic structure and dynamics for space weather prediction.

Contribution

It provides the first clear detection of neutral helium in eruptive prominences at the middle corona using He I 1083 nm, enhancing the capability to monitor and understand CME-related eruptions.

Findings

Prominence eruptions are detectable in He I 1083 nm up to 2 solar radii.

UCoMP can estimate line-of-sight velocities of eruptions.

He I 1083 nm observations complement EUV and white-light imaging for CME analysis.

Abstract

Coronal mass ejections (CMEs) are a major driver of space weather as they propagate through the heliosphere. Many CMEs have associated prominence material entangled in their magnetic structure which contains cooler plasma. This cooler CME component contains significant amounts of neutral elements, which emit brightly in permitted atomic lines. It has been hypothesized that permitted transitions of neutral elements in eruptions could be used for inferring the magnetic field in CMEs, which is crucial for space weather forecasting. We present observations made with the Upgraded Coronal Multi-channel Polarimeter (UCoMP) in He I 1083 nm that clearly show the presence of neutral helium in eruptive prominences associated with CMEs as they propagate through the lower and middle corona. We find that solar prominence eruptions can be detected in He I 1083 nm observations up to the edge of the instrument field of view at about 2 solar radii, providing valuable spectral information that complements existing extreme ultraviolet and white-light coronal imaging observatories. These results illustrate the capability of UCoMP to probe the dynamic behavior of prominence eruptions, allowing for their line-of-sight velocity estimation, and potentially improving space weather forecasting by enabling earlier and more accurate identification of Earth-directed eruptions.