Solar Eclipse Observations from the Ground and Air from 0.31 to 5.5 Microns

Judge, P. G.; Berkey, Benjamin; Boll, Alyssa; Bryans, P.; Burkepile, J.; Cheimets, Peter; Edward, DeLuca; Toma, G. de; Gibson, K. L.; Golub, L.; Hannigan, J. W.; Madsen, C. A.; Marquez, Vanessa; Richards, A.; Samra, Jenna; Sewell, Scott; Tomczyk, S.; Vera, Alysha

doi:10.1007/s11207-019-1550-3

Cited by 14 publications

(13 citation statements)

References 28 publications

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“…However, Kuhn et al (1996) reported eclipse measurements where the 10830 Å line has a brightness comparable to those of the Fe XIII NIR forbidden lines, out to some radial distances. This was later confirmed by other ground-based observations, see e.g Kuhn et al (2007); Moise et al (2010); Judge et al (2019). Kuhn et al (2007) pointed out that the width of the line was much narrower than the coronal Fe XIII NIR forbidden lines, indicating that the emission in this line is not coronal in origin.…”

Section: Introductionsupporting

confidence: 74%

Helium line emissivities in the solar corona

Del Zanna,

Storey,

Badnell

et al. 2020

Preprint

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We present new collisional-radiative models (CRMs) for helium in the quiescent solar corona, and predict the emissivities of the He and He + lines to be observed by DKIST, Solar Orbiter, and Proba-3. We discuss in detail the rates we selected for these models, highlighting several shortcomings we have found in previous work. As no previous complete and self-consistent coronal CRM for helium existed, we have benchmarked our largest model at a density of 10 6 cm −3 and temperature of 20,000 K against recent CRMs developed for photoionised nebulae. We then present results for the outer solar corona, using new dielectronic recombination rates we have calculated, which increase the abundance of neutral helium by about a factor of two. We also find that all the optical triplet He I lines, and in particular the well known He I 10830 and 5876 Å lines are strongly affected by both photo-excitation and photo-ionisation from the disk radiation, and that extensive CRM models are required to obtain correct estimates. Close to the Sun, at an electron density of 10 8 cm −3 and temperature of 1 MK, we predict the emissivity of the He I 10830 Å to be comparable to that of the strong Fe XIII coronal line at 10798 Å. However, we expect the He I emissivity to sharply fall in the outer corona, with respect to Fe XIII. We confirm that the He + Lyman α at 304 Å is also significantly affected by photo-excitation and is expected to be detectable as a strong coronal line up to several solar radii.

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Section: Introductionsupporting

confidence: 74%

Helium line emissivities in the solar corona

Del Zanna,

Storey,

Badnell

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

“…However, Kuhn et al (1996) reported eclipse measurements where the 10830 Å line has a brightness comparable to that of the Fe XIII NIR forbidden lines, out to some radial distances. This was later confirmed by other ground-based observations; see, e.g., Kuhn et al (2007), Moise et al (2010), and Judge et al (2019). Kuhn et al (2007) pointed out that the width of the line was much narrower than the coronal Fe XIII NIR forbidden lines, indicating that the emission in this line is not coronal in origin.…”

Section: Introductionsupporting

confidence: 73%

Helium Line Emissivities in the Solar Corona

Zanna

Storey

Badnell

et al. 2020

ApJ

View full text Add to dashboard Cite

We present new collisional-radiative models (CRMs) for helium in the quiescent solar corona and predict the emissivities of the He and He + lines to be observed by DKIST, Solar Orbiter, and Proba-3. We discuss in detail the rates we selected for these models, highlighting several shortcomings we have found in previous work. As no previous complete and self-consistent coronal CRM for helium existed, we have benchmarked our largest model at a density of 10 6 cm −3 and temperature of 20,000 K against recent CRMs developed for photoionized nebulae. We then present results for the outer solar corona, using new dielectronic recombination rates we have calculated, which increase the abundance of neutral helium by about a factor of 2. We also find that all optical triplet He I lines, and in particular the well-known He I 10830 and 5876 Å lines, are strongly affected by both photoexcitation and photoionization from the disk radiation and that extensive CRMs are required to obtain correct estimates. Close to the Sun, at an electron density of 10 8 cm −3 and temperature of 1 MK, we predict the emissivity of He I 10830 Å to be comparable to that of the strong Fe XIII coronal line at 10798 Å. However, we expect the He I emissivity to sharply fall in the outer corona, with respect to Fe XIII. We confirm that the He + Lyα at 304 Å is also significantly affected by photoexcitation and is expected to be detectable as a strong coronal line up to several solar radii.

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“…This work is therefore critical to prepare for meaningful observations of coronal M1 lines on a routine basis. The necessity mentioned by Judge (1998) for improved measurements to assess the completeness and accuracy of theoretical spectroscopic work is important to note, aligning with conclusions of needing to perform high resolution spectral analysis of absorption spectra in proximity of coronal emission, shown by Judge et al (2019). This kind of analysis can be performed on data like the airborne AIR-Spec measurements analyzed by Samra et al (2018), or data obtained from ground-based instruments like the FTS provided via the high-resolution McMath-Pierce atlas, which we utilize here.…”

Section: Introductionmentioning

confidence: 80%

“…More recently, Judge et al (2019) surveyed spectra at thermal IR wavelengths and presented broadband polarized light data captured during the 2017 total solar eclipse while testing new technologies for measuring polarized coronal light. Spectra of the limb photosphere, chromosphere, prominences, and coronal lines from 310 nm to 5.5 µm were all analyzed for this experiment.…”

Section: Introductionmentioning

confidence: 99%

A spectroscopic survey of infrared 1-4μm spectra in regions of prominent solar coronal emission lines of Fe XIII, Si X, and Si IX

Ali,

Paraschiv,

Reardon

et al. 2022

Preprint

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The infrared solar spectrum contains a wealth of physical data about the Sun and is being explored using modern detectors and technology with new ground-based solar telescopes. One such instrument will be the ground-based Cryogenic Near-IR Spectro-Polarimeter of the Daniel K. Inouye Solar Telescope that will be capable of sensitive imaging of the faint infrared solar coronal spectra with full Stokes I, Q, U, and V polarization states. Highly ionized magnetic dipole emission lines have been observed in galaxies and the solar corona. Quantifying the accuracy of spectral inversion procedures requires a precise spectroscopic calibration of observations. A careful interpretation of the spectra around prominent magnetic dipole lines is essential for deriving physical parameters, and particularly, for quantifying the off-limb solar coronal observations from DKIST. In this work, we aim to provide an analysis of the spectral regions around the infrared coronal emission lines of Fe XIII 1074.68 nm, Fe XIII 1079.79 nm, Si X 1430.10 nm, and Si IX 3934.34 nm, aligning with the goal of identifying solar photospheric and telluric lines that will help facilitate production of reliable inversions and data products from four sets of solar coronal observations. The outputs will be integrated in the processing pipeline to produce Level-2 science-ready data that will be made available to DKIST observers.

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Solar Eclipse Observations from the Ground and Air from 0.31 to 5.5 Microns

Cited by 14 publications

References 28 publications

Helium line emissivities in the solar corona

Helium line emissivities in the solar corona

Helium Line Emissivities in the Solar Corona

A spectroscopic survey of infrared 1-4μm spectra in regions of prominent solar coronal emission lines of Fe XIII, Si X, and Si IX

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