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Full-Text Articles in Physical Sciences and Mathematics

Opacities Of S-Type Stars: The Singlet B¹⊓−X¹Σ⁺, B¹⊓−A¹Δ, And C¹Σ⁺−X¹Σ⁺ Band Systems Of Zro, Peter F. Bernath, Manish Bhusal, Jacques Liévin Jan 2024

Opacities Of S-Type Stars: The Singlet B¹⊓−X¹Σ⁺, B¹⊓−A¹Δ, And C¹Σ⁺−X¹Σ⁺ Band Systems Of Zro, Peter F. Bernath, Manish Bhusal, Jacques Liévin

Chemistry & Biochemistry Faculty Publications

The ZrO B1Π–X1Σ+, B1Π–A1Δ, and C1Σ+–X1Σ+ band systems are important opacity sources in the near-infrared and optical spectra of S-type stars. A total of 21 rovibronic bands with v'' ≤ 7 and v' ⩽ 5 were observed and fit for the B1Π–X1Σ+ transition, five bands for the 90ZrO B1Π–A1Δ transition and one band for the 90ZrO C1Σ+X1Σ+ transition. All band …


S-Type Stars: Line List For The A²Π-X²Σ⁺ Band System Of Lao, P. F. Bernath, R. Dodangodage, J. Liévin Jan 2023

S-Type Stars: Line List For The A²Π-X²Σ⁺ Band System Of Lao, P. F. Bernath, R. Dodangodage, J. Liévin

Chemistry & Biochemistry Faculty Publications

LaO bands are found in the spectra of cool S-type stars. The bands of the A2Π–X2Σ+ transition with v' ⩽ 3 and v'' ≤ 4 are rotationally analyzed, providing spectroscopic constants for the A2Π state. Line strengths are calculated using an ab initio transition dipole moment function, and radiative lifetimes for the A2Π state have also been computed. A line list for the A2Π–X2Σ+ transition of LaO is provided and can be used to determine LaO stellar abundances.


Visible Opacity Of M Dwarfs And Hot Jupiters: The Tio B³Π-X³Δ Band System, W. Doug Cameron, Peter Bernath Jan 2022

Visible Opacity Of M Dwarfs And Hot Jupiters: The Tio B³Π-X³Δ Band System, W. Doug Cameron, Peter Bernath

Chemistry & Biochemistry Faculty Publications

The TiO B3Π−X3Δ electronic transition (𝛾' system) is an important opacity source in the atmospheres of M dwarfs and hot Jupiter exoplanets. The 0–0, 1–0, and 2–1 bands of the B3Π−X3Δ band system have been analyzed using a TiO emission spectrum recorded at the McMath-Pierce Solar Telescope, operated by the National Solar Observatory at Kitt Peak, Arizona. Improved spectroscopic and equilibrium constants were determined. Line strengths were calculated from an ab initio transition-dipole moment function scaled using an experimental lifetime. A new line list for v' = 0–2 and v′′ = 0–4 …


S-Type Stars: Lao Line List For The B²Σ⁺-X²Σ⁺ Band System, P. F. Bernath, Randika Dodangodage, J. Liévin Jan 2022

S-Type Stars: Lao Line List For The B²Σ⁺-X²Σ⁺ Band System, P. F. Bernath, Randika Dodangodage, J. Liévin

Chemistry & Biochemistry Faculty Publications

LaO bands are a characteristic feature in the spectrum of cool S-type stars. La is made primarily by the s-process during the asymptotic giant branch phase of stellar evolution. The B2Σ+–X2Σ+ and A2Π–X2Σ+ band systems can be used to determine the La abundances in cool S stars. The bands of the B2Σ+–X2Σ+ with v' and v" ⩽ 5 have been rotationally analyzed from an emission spectrum from a carbon furnace. Line strengths are calculated using an ab initio transition dipole …


Near-Infrared And Visible Opacities Of S-Type Stars: The B¹Π—X¹Σ⁺ Band System Of Zro, Jason J. Sorensen, Peter F. Bernath Jan 2021

Near-Infrared And Visible Opacities Of S-Type Stars: The B¹Π—X¹Σ⁺ Band System Of Zro, Jason J. Sorensen, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

The ZrO B1Π—X1Σ+ transition is an important opacity source in the near-infrared and optical spectrum of S-type stars. The 0–0, 0–1, 0–2, 1–0, 1–2, 1–3, 2–0, 2–1, 2–3, 2–4, 3–1, 3–4, and 4–2 bands of the 90Zr16O B1Π—X1Σ+ transition are reanalyzed using a high-temperature (2390 K) high-resolution (0.04 cm−1) emission spectrum collected at the National Solar Observatory (Kitt Peak). A modern spectroscopic analysis was performed using the PGOPHER program to provide updated spectroscopic constants and to produce a high-precision line list with line strengths based on an …


Measured Optical Absorption Cross Sections Of Tio, Peter Bernath Jan 2020

Measured Optical Absorption Cross Sections Of Tio, Peter Bernath

Chemistry & Biochemistry Faculty Publications

A laboratory emission spectrum of TiO in the visible and near-infrared regions (476–1176 nm) has been calibrated and corrected. High-resolution experimental absorption cross sections for TiO with natural isotopic abundance are provided at a temperature of about 2300 K. These cross sections have been compared with those derived from the ExoMol line list. The experimental cross sections can be used directly as a template for cross correlation TiO detection in hot Jupiter exoplanets.


Neutron Star Electromagnetic Field Structure, Hugh O. Thurman Iii Apr 2004

Neutron Star Electromagnetic Field Structure, Hugh O. Thurman Iii

Physics Theses & Dissertations

This dissertation investigates the neutron star magnetic field from generation to radiation production. We have investigated the spontaneous magnetization process to explain the magnetic field generation. This magnetization is then applied to determine the electromagnetic field structure of the neutron star. As an application of these two calculations, we briefly investigate several radiation mechanisms that are closely related to stellar magnetic fields.

Neutron star magnetic field generation is studied through the spontaneous magnetization process. This process was studied in the non-relativistic, ultra-relativistic, and rigorous relativistic dispersion regimes for the neutrons. Both analytical and numerical approaches show that a phase transition …