Stars, Interstellar Medium and the Galaxy Commons^™

Variability On M-Dwarf Stars And Its Effect On Exoplanet Detection, Aylin Garcia Soto

Dartmouth College Ph.D Dissertations

Understanding stellar magnetic activity is crucial for exoplanet research: activity can mask signatures from exoplanet detection and characterization, and impact planetary habitability. This is particularly important for M dwarf stars, which are highly magnetically active, displaying spectroscopic and photometric signatures of flares and rotational variability. In this thesis, I will present two complementary perspectives on M dwarf magnetic activity. First, I will discuss a study of short-term variability. I made new ground-based observations of 77 M dwarfs and tested the connection between chromospheric emission and photometric variability. I find a weak positive correlation between H$\alpha$ luminosity (tracing magnetic heating) and …

Fsc Will Have A 'Big Eye', Bob Dixon

Documents

News article from The Florence Times about the new 14 1/2-inch reflector telescope built and donated to Florence State College.

Using Ngc 2168 To Calibrate Ages For Individual Stars, Skylar G. Butler

Beyond: Undergraduate Research Journal

This research investigates the precision and accuracy of age determination in open star clusters using BASE-9 software. The project is divided into two parts, with the first being the determination of the age of the entire cluster and the second being the age determination of the individual stars within the NGC 2168 cluster. Part one involves analyzing the collective properties of the cluster to derive its age. Part two involves assessing the age of individual stars within the selected star clusters using BASE-9 software. We will evaluate the reliability and validity of the age determinations obtained by analyzing individual stars …

Spectroscopy And Photochemistry Of The Astrochemical Molecules Sicp And Alcp, Vincent J. Esposito, Tarek Trabelsi, Rebecca Firth, Ryan C. Fortenberry, Joseph S. Francisco

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Through characterization of the electronic excited-state topology, linear-SiCP is predicted to be photostable in the UV region, whereas linear-AlCP is predicted to undergo photodissociation to form Al+CP products after absorption of light in the 200–250 nm range, representing a catalytic process for freeing aluminum molecules from a solid dust grain. Both SiCP and AlCP are predicted to have electronic transitions with large absorption cross sections (∼10^–17 cm²) and to undergo fluorescence from bound excited states. The total electronic absorption spectrum is provided to inform electronic spectroscopy experiments. Silicon (SiC) and aluminum (Al₂O₃) dust …

Constraining The Impact Threat From Small Bodies In Near Earth And Cislunar Space, Skylar G. Butler, Jarrett Dieterle, Henry Sanders, Aiden Kelleher

Student Research Symposium (SRS)

Understanding and mitigating the impact threat posed by small bodies in near-Earth and cislunar space is vital for planetary defense, spacecraft safety, and sustainable space operations. This research integrates dynamical evolution modeling, synthetic observations, and reprocessed infrared data to assess the origins and potential hazards of debris from young asteroid families. By modeling the trajectories and orbital evolution of fragments from the Datura, Emilkowalski, 1992 YC2, Lucascavin (Nesvorný & Vokrouhlický, 2006), and Veritas (Nesvorný et al., 2003) families, we constrain how these sources contribute to near-Earth debris populations. Reprocessing Infrared Astronomical Satellite (IRAS) data with Fourier-filtering techniques reveals fine-structure variations …

Solar Wind–Magnetosphere Coupling During The September 2025 Cme: Multi-Spacecraft Analysis Using Mms And Omni Data, Skylar G. Butler, Margret Stanley

Student Research Symposium (SRS)

A sequence of two coronal mass ejections (CMEs) impacted Earth in early September 2025, producing consecutive geomagnetic disturbances. The first CME, launched on 31 August 2025 and observed as a halo in SOHO/LASCO imagery, reached Earth on 1 September (~20:45 UTC), generating a clear interplanetary shock. OMNI 1-min solar-wind data show a sudden rise in |B| from ≈ 5 nT to > 25 nT, proton density and velocity increases (≈ 350 → 600 km s⁻¹), and a southward IMF Bz interval that drove enhanced coupling. The Kyoto Dst index recorded a sudden storm commencement followed by a minimum of −75 nT …

How Hidden Companions Skew Stellar Ages: A Binary-Inclusive Analysis Of Ngc 2168, Skylar G. Butler

Student Research Symposium (SRS)

We expand upon our previous analysis of NGC 2168 (M35), which investigated the precision of isochrone-based age determination for individual main-sequence stars using photometric modeling. Building on that earlier framework, we now assess how inferred stellar ages change when each object is modeled under the assumption that it may possess an unresolved binary companion. Using post burn in posterior samples from the same dataset, we computed the mean Stage 3 ages for more than 3,000 cluster members with binaries turned on, allowing a direct comparison to our prior results with binaries turned off. The resulting age distribution peaks near 2.1 …

Modeling The Secondary Catastrophic Disruption Of The Veritas Family, Jarrett Dieterle, Skylar G. Butler, Aiden Kelleher

Student Research Symposium (SRS)

The Veritas asteroid family, located in the outer main belt, is believed to have formed from the catastrophic breakup of a parent body approximately 8.3 million years ago (e.g., Nesvorný et al., 2003). Larger fragments remained in the main belt, while smaller particles evolved inward under radiation forces, forming a toroidal dust structure observable in infrared data as paired bands. Previous studies (e.g., Dermott et al., 2001) have shown that these bands can be linked to their parent families and modeled from their initial disruptions. We propose that the 10° dust bands associated with Veritas may record evidence of a …

Building The Erau Solar Telescope: Advancing Heliophysics Research And Education Through Optical Innovation, Erin Abraham, Sarah Hoover, Skylar G. Butler, Margret Stanley, Gwynlyn Hannah

Student Research Symposium (SRS)

The new Embry-Riddle Aeronautical University (ERAU) Solar Telescope represents a campus-wide collaboration to design and install a high-resolution solar observatory. The ERAU solar telescope, aiming for first light by Summer 2026, will integrate research-grade instrumentation, student training opportunities, and expand public engagement with the ERAU observatory. The telescope is housed within a 2.3-meter refurbished dome structure whose electrical and structural systems are being upgraded to support automated dome rotation and environmental stabilization. The optical design features a multi-element lens and mirror assembly optimized for a 1° field of view. The optical assembly includes a downport centered in the dome that …

Contact Binary Stars: A Roadmap To Their Nature And Evolution, Larry A. Molnar, M. Chalov, R. Deaton, R. Reynolds

University Faculty Publications and Creative Works

A complete life cycle for W UMa systems

• Mass transfer from secondary driven by primary
• Sign of flow essential to stability criteria 
• Consistent with observations of distributions of M, T, P, q, dP/dt, (P,q)merger

Ongoing

• THEORY 
• Understand f distribution 
• Compute grid of models to compare with populations of various ages • 

OBSERVATION:Rubin observatory data

• Establish parameter distributions vs. location or kinematics 
• Find the next red nova before it explodes

M-Type Star Spectral Analysis: Sco Line List Including The B²Σ⁺-X²Σ⁺ Band System, Léo Lavy, Jacques Liévin, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

An analysis of the B²Σ⁺ − X²Σ⁺ band system of ⁴⁵Sc¹⁶O is presented. ScO was excited in a hollow cathode discharge, and its Doppler-limited resolution spectrum was measured with a Fourier transform spectrometer. The spectroscopic constants of the B²Σ⁺ state with v ≤ 3 are reported, and equilibrium constants are derived. Ab initio transition dipole moment functions are calculated for the A²Π − X²Σ⁺ and B²Σ⁺ − X²Σ⁺ transitions and scaled using lifetime measurements. We report new line lists of hyperfine-resolved transitions for ⁴⁵Sc¹⁶O with recalculated Einstein A coefficients and oscillator strengths of the …

An Application Of Molecular Dynamics To Hed Plasma Physics: Point And Group Defect Diffusion In Coulomb Crystals, Levi Webb

Theses and Dissertations

Molecular dynamics (MD) simulations are used to explore the microscopic behaviors of complex systems that cannot be easily studied experimentally. In particular, the microphysics of high energy density (HED) astrophysical plasma environments remain inaccessible by modern experiment---even in laser facilities, these plasmas exist only on short timescales that do not lend easily to investigation. The diffusion of point and group defects through crystallized plasmas in the cores of white dwarfs and neutron star crusts, called Coulomb crystals, has potentially macroscopic implications for the evolution of these bodies. Thus, I employ the widely-used MD code LAMMPS to simulate small Coulomb crystal …

Additional Information For Fully Anharmonic Ir Spectra Of Neutral Polycyclic Aromatic Hydrocarbons With Up To 38 Carbons, Nolan J. H. White, Vincent J. Esposito, Christiaan Boersma, Louis J. Allamandola, Jesse D. Bregman, Alexandros Maragkoudakis, Pasquale Temi, Ryan C. Fortenberry

Faculty and Student Publications

Interstellar aromatic infrared band (AIB) spectra are showing strong agreement with presently-computed, anharmonic spectra for various types of polycyclic aromatic hydrocarbons (PAH) determined using a novel semi-empirical quantum chemical method. Since the AIB spectrum is a blend of emission spectra from a vast number of different PAHs, likely with an array of different molecular structures, the spectra for a sample set of 31 PAHs ranging in size from naphthalene (C$_{10}$H$_8$) up to circumbiphenyl (C$_{38}$H$_{16}$) are combined giving consideration to almost all PAH structural motifs. The computed, numerical quartic force fields coupled to second-order vibrational perturbation theory clearly confirm that PAH …

Timing, Spectral, And Single-Pulse Properties Of Radio Pulsars, Evan Francis Lewis

Graduate Theses, Dissertations, and Problem Reports (ETD)

Radio pulsars are highly magnetized, rapidly rotating neutron stars which emit beams of radio waves from their magnetic poles. Their incredible rotational stability allows for their use in a variety of high-energy astrophysical studies, though the details of their internal structure and emission mechanisms are still unknown. We use observations of a cross-section of the pulsar population in order to investigate the nature of their evolution, their emission properties, and their environments.

First we derive timing solutions for three pulsars discovered through their sporadic single pulses. It was possible to obtain timing solutions through a set of single-pulse times of …

An Updated Infrared Solar Spectrum From Ace-Fts And A Ch Rovibrational Line List, Manish Bhusal, Peter F. Bernath, Léo Lavy, Chris D. Boone, Frank Hase

Chemistry & Biochemistry Faculty Publications

An updated Atmospheric Chemistry Experiment Fourier Transform Spectrometer infrared solar spectrum has been produced from low-Earth orbit covering 1829-4440 cm^-¹ (2.252-5.467 mu m). Spectroscopic constants for the v = 4 and v = 5 vibrational levels of the X²Π state of CH radical have been updated by incorporating additional vibration-rotation lines from the new solar spectrum and from an archival laboratory spectrum. New ab initio calculations of the permanent dipole moment function for the X²Π state were performed with the MOLPRO quantum chemistry package using the internally contracted multireference configuration interaction method. This dipole moment function, along with …

Numerical Modeling Of Multi-Scale Jet Feedback In Seyfert Galaxies, Julianne Goddard

Theses and Dissertations--Physics and Astronomy

We present a suite of high-resolution cosmological zoom-in simulations investigating the impact of mechanical and thermal feedback from low-luminosity jets launched from supermassive black holes (SMBHs) on Seyfert galaxy evolution from early cosmic times to the present (z ≤ 10). Our models follow the formation of central galaxies within identical dark matter halos of logMhalo/M⊙ ∼ 11.8 at z = 0, seeded with ∼ 10^6M⊙ SMBHs at z ∼ 9.1 and z ∼ 3.7. Feedback from active galactic nuclei (AGN) is implemented in the form of bipolar jets launched along the SMBH spin axis, with jet powers spanning Ljet ∼ …

The Aurora Survey: Robust Helium Abundances At High Redshift Reveal A Subpopulation Of Helium-Enhanced Galaxies In The Early Universe, Danielle A. Berg, Ryan L. Sanders, Alice E. Shapley, Michael W. Topping, Naveen A. Reddy, Evan D. Skillman, Erik Aver, Fergus Cullen, Callum T. Donnan, James S. Dunlop, Tucker Jones, Ali Ahmad Khostovan, Derek J. Mcleod, Desika Narayanan, Pascal A. Oesch, Anthony J. Pahl, Max Pettini, N. M. Förster Schreiber, Daniel P. Stark

Physics Faculty Scholarship

We present the first robust helium (He) abundance measurements in star-forming galaxies at redshifts 1.6 ≲ z ≲ 3.3 using deep, moderate-resolution JWST/NIRSpec spectroscopy from the AURORA survey. We establish a high-z He sample consisting of 20 galaxies with multiple high-signal-to-noise-ratio (>5σ) He i emission-line detections, including the critical near-infrared λ10833 line. This is the first study at high redshift leveraging λ10833 to break degeneracies between temperature, electron density, optical depth, and He+/H+, enabling reliable He abundance determinations in the early Universe. We use a custom Markov Chain Monte Carlo framework incorporating direct-method electron …

Stars And Shapes: An Investigation Of Stripped Envelope Supernovae Structures Using Spectropolarimetry Observations And Hydrodynamic Models, Sabrina Desoto

Electronic Theses and Dissertations

Supernovae (SNe) are the energetic deaths of massive stars, dispersing heavy elements throughout the galaxies and shaping cosmic evolution across the universe. However, understanding the connections between the evolution of massive stars, their catastrophic demises, and the myriad of observed SNe, remains a fundamental challenge in astrophysics. My work aims to narrow this gap by integrating extensive observational data with advanced hydrodynamical simulations to better interpret SNe observations and understand the origin of their geometry. The observational component utilizes the largest spectropolarimetry dataset of stripped-envelope (SE) core-collapse supernovae (CCSNe) gathered by the SNSPOL project. Analyzing nine Type Ib and eleven …

Determining The 17f(Α,P)20ne Reaction Rate For Application In Type I X-Ray Bursts, William Braverman

LSU Doctoral Dissertations

The ¹⁷F(α, p)²⁰Ne reaction has been identified as an alternate pathway for breakout from the hot-CNO cycle that can be important in some X-ray burst scenarios. The ¹⁷F(α, p)²⁰Ne reaction rate was previously determined through a parameterized exponential S-factor with a large enhancement from thermally-excited states based on statistical models with large uncertainties. We have measured the time-inverse ²⁰Ne(p,α)¹⁷F cross section at center-of-mass energies ranging from 5.50 to 7.10 MeV using an activation method with a proton beam on a neon gas cell. Coincident detections of 511-keV γ-rays, resulting from electron-positron …

Numerical Simulations Of Highly Eccentric Systems Of Binary Neutron Stars With Spin, Victoria White

Harriet L Wilkes Honors College Theses

Binary Neutron Star (BNS) mergers are among the most energetic events in the universe, producing gravitational waves, electromagnetic radiation, and heavy elements. While previous research has utilized simulations for collisions, few studies have accounted for how the spin of the stars affects mergers. This thesis contains a general overview of the topic and a research component conducted in the field of numerical relativity. High-performance computing was used to simulate BNS collisions, examining how spin affects the inspiral, merger, and post-merger phases. Computations used the Einstein Toolkit, Cactus framework, and the numerical tool developed by the FAU Relativity Group, Sgrid. The …