Saved in:
Bibliographic Details
Main Authors: Molnar, M. E., Casini, R., Bryans, P., Berkey, B., Tyson, K.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2501.01009
Tags: Add Tag
No Tags, Be the first to tag this record!
Table of Contents:
  • Strong He I 1083 nm atomic line signals have been previously measured during total solar eclipses at coronal heights above the lunar limb. This rather unexpected measurement has kindled a discussion about the hypothesized presence of significant amounts of neutral helium at coronal conditions. We performed spectroscopic observations of the He I 1083 nm spectroscopic region with the newly built CHEESE instrument during the April 8th 2024 total solar eclipse to test the presence of He I 1083 in the solar corona. We detected the He I 1083, the forbidden coronal line Fe XIII 1074.7 nm, as well as the chromospheric H I 1093.8 nm Paschen-γ line in our eclipse observations. The chromospheric He I 1083 and H I 1093.8 nm Paschen-γ lines are detected in the corona as well as on the lunar disc. Our findings point toward a non-solar origin of the He I 1083 signal during the April 8th 2024 eclipse that challenge the notion of abundant neutral helium in the solar corona inferred from eclipse observations.