Identification

Title

Detection of â€œdiffuseâ€ coronal He I 1083 during the April 8, 2024 solar eclipse: Evidence for terrestrial atmospheric scattering contribution

Abstract

Strong He i 1083 nm atomic line signals have previously been measured during total solar eclipses at coronal heights above the lunar limb. These rather unexpected measurements have kindled a discussion about the suggested presence of significant amounts of neutral helium at coronal conditions. We performed spectroscopic observations of the He i 1083 nm wavelength region during the April 8th, 2024 total solar eclipse, using an instrument specifically designed to test the presence of He i 1083 in the solar corona. We were able to detect the He i 1083 line, the forbidden coronal line of Fe xiii at 1074.7 nm, as well as the chromospheric H i 1093.8 nm (Paschen- ) line in our data. The chromospheric He i 1083 nm and H i 1093.8 nm lines were detected in both the corona and on the lunar disc. We hypothesize that our observations support a terrestrial atmospheric scattering of the solar flash spectrum as the origin of the He i 1083 signal during the April 8th, 2024 eclipse. Our findings challenge the notion of abundant neutral helium in the solar corona suggested by previous eclipse observations.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d7ht2ts2

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

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East bounding longitude

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Temporal reference

Temporal extent

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date type

publication

effective date

2025-07-01T00:00:00Z

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Use constraints

<span style="font-family:Arial;font-size:10pt;font-style:normal;" data-sheets-root="1">Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</span>

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact