Terrestrial Atmospheric Scattering Origin of Coronal He I 1083 nm Eclipse Emission
During total solar eclipses, the He I 1083 nm neutral-helium line has been seen far above the solar limb, suggesting abundant neutral helium in the corona. Using the CHEESE near-IR spectrograph, this work shows the line also appears on the lunar disc with a chromospheric thermal width and brightens toward the flash spectrum, arguing the signal is scattered chromospheric flash-spectrum light in Earth's atmosphere rather than coronal neutral helium. Students learn how eclipse spectroscopy and line-width diagnostics distinguish a genuine coronal signal from a terrestrial scattering artifact.
Solar Physics DOI: 10.1007/•••••-•••-•••-••••-• Detection of “diffuse” coronal He I 1083 during the
The paper reports observations from CHEESE, a purpose-built near-infrared slit spectrograph deployed at the April 8 2024 total solar eclipse to test the origin of the diffuse He I 1083 nm emission se…