Astrophysics and Astronomy Commons^™

What Do Black Holes Teach Us About Wigner’S Friend?, Emily Adlam

Mathematics, Physics, and Computer Science Faculty Articles and Research

Recently, Hausmann and Renner have pointed out that several famous paradoxes relating to black holes have a similar character to various Extended Wigner’s Friend paradoxes. In this paper I consider what the connection between these things could teach us about the Wigner’s Friend scenarios. I argue that if we take the analogy between these cases seriously, the black hole paradoxes appear to favour a certain class of response to the Wigner’s Friend scenario - specifically, those which posit intrinsic relationality, rather than effective and emergent relationality, and also those which posit some kind of retrocausality.

Domain Wall Gravitational Waves: Constraints Within Extensions Of The Standard Model, Sophia W. Jensen

Departmental Honors & Graduate Capstone Projects

This work considers an extra-dimensional framework to explain the gravitational wave background (GWB), massive neutrinos, and baryon asymmetry. Through studying all three, restrictions on certain parameters arise and provide bounds on both theories. It is proposed that the GWB is caused by cosmic domain walls, sheet-like topological defects that were theoretically created in the early universe shortly after the Big Bang. A relationship be- tween the energy density of domain walls and the vacuum expectation value of the broken symmetry was defined. Constraints on the parameters, including the already observed fre- quencies of gravitational waves and the current energy content …

Intermediate-Scale Outflow Dynamics Of Eta Carinae, Edmund J. Garcia, Matthew C. Fleenor

Departmental Honors & Graduate Capstone Projects

η Carinae (η Car) is a binary system, with the larger star being an extremely massive, luminous blue variable (LBV) beyond the Eddington Limit. Surrounding the η Car system, numerous multi-wavelength imaging campaigns reveal axisymmetric structures with the expanding bipolar Homunculus Nebula (¡1 pc). In combination with the episodic eruptive history of the η Car system, our initial intermediate-scale imaging revealed further axisym- metric structures (1-5 pc). To gain a more expansive view of how the small scale structure connects to panoramic imaging of the η Car region, we constructed a deep, optical, narrowband mosaic of 189 images utilizing the …

All-Sky Search For Long-Duration Gravitational-Wave Transients In The First Part Of The Fourth Ligo-Virgo-Kagra Observing Run, A. G. Abac, I. Abouelfettouh, F. Acernese, Teviet Creighton, Mario C. Diaz, Raul A. Espinosa, J. Lawrence, Francisco Llamas Villarreal, Soma Mukherjee, Volker Quetschke, Miriam Ramos Arevalo, Wenhui Wang

Physics & Astronomy Faculty Publications

We present an all-sky search for long-duration gravitational waves (GWs) from the first part of the LIGO-Virgo-KAGRA fourth observing run (O4), called O4a and comprising data taken between May 24, 2023, and January 16, 2024. The GW signals targeted by this search are the so-called “long-duration” ( ≳1  s) transients expected from a variety of astrophysical processes, including nonaxisymmetric deformations in magnetars or eccentric binary coalescences. We make minimal assumptions on the emitted GW waveforms in terms of morphologies and durations. Overall, our search targets signals with durations of ∼1–1000  s and frequency content in the range 16–2048 Hz. In …

The Role Of Human-Centered Artificial Intelligence In Crewed Mars Missions, Jordan Neuman

Student Publications and Presentations

The suggestion of implementing Artificial Intelligence (AI) in crewed missions to the Martian surface can revolutionize mission operations, psychological support, and ethical decision‑making under challenging conditions. This study is a structured, qualitative literature review of current AI research for the future of human space exploration. It uses publicly available peer‑reviewed journal articles and NASA/ESA technical reports on AI for Mars missions. Using Perplexity, the researcher first prompted the AI tool to identify recurring topics across these sources and generate themes. The researcher independently reviewed all sources to confirm and refine those themes. Three themes—mission autonomy, local resource utilization and life‑support, …

Tracing The Milky Way’S Evolution Through Its Star-Planet Systems, Rayna Rampalli

Dartmouth College Ph.D Dissertations

From individual planetary systems to the Milky Way's structure, stars are the linchpin connecting astrophysical scales. Through three complementary projects, my thesis leverages these connections and large stellar surveys to offer insight into the Galaxy's dynamical and chemical history and its role in shaping planet formation and evolution. (I) I developed Protify, an automated pipeline to measure stellar rotation periods in TESS light curves, enabling rotation-based ages for thousands of stars. Applying it to overdensities of stars in eccentric Galactic orbits, thought to be post-resonant signatures of spiral arm passages, revealed unexpectedly young rotators in dynamically old populations. Because such …

Measuring Cosmic Rays With Muon Detectors (Quarknet), Jack W. Maseberg

SACAD: Scholarly Activities

We report measurements of atmospheric muon particles originating from cosmic rays. Using four QuarkNet project scintillators in a stacked geometry, we recorded muons in coincidence with each other. We observed a change in the muon flux due to a solar Coronal Mass Ejection (CME) event on Jan 19, 2026.

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 …

Interacting Dark Energy Models And The Cosmic Coincidence Problem, Gunner W. Hodges

ATU Scholars Symposium

Cosmological models are a tool used to understand the mysterious nature of dark energy and dark matter by predicting how these dark sector components have shaped the expansion of the universe. The cosmic coincidence problem stems from the present day densities of dark energy and matter sharing very similar magnitudes when previously we expect a much larger difference in orders of magnitude. The current best-fit model, ΛCDM , assumes dark energy is non-interacting; however, assuming that dark energy instead does interact could serve to alleviate this cosmic tension. We define an interaction where we relate the density of dark energy …

Energy Scaling And Frequency Ratios Of Particles And Constants, Alison Christina Menzmer, Donald Chakeres, Vola Andrianarijaona

Campus Research Month

We are exploring quantum aspects of various physical quantities (including Bohr radius, Rydberg constant, Planck time, and Hubble constant) and mass energies of elementary particles (including electron, neutron, and quarks). We express all physical units in an energy equivalence in Hertz, normalized to 1 Hz. Furthermore, the logarithms of these normalized energies are scaled by the logarithm of a chosen particle, which allows the generation of an Arrhenius plot exhibiting numerical structures. Our results presented in this poster show that the proton is a good candidate for an Arrhenius plot with partial fractions (1 + 1/n) and (1 - 1/n).

Searching Within Galaxies For The Earliest Signs Of Quenching With Spatially Resolved Star Formation Histories In Uvcandels Galaxies At Z < 0.3, Charlotte Olsen, Eric Gawiser, Charlotte Welker, Harry Teplitz, Kartheik Iyer, Xin Wang, Marc Rafelski, Rogier A. Windhorst, Anton Koekemoer, Anahita Alavi, Ben Sunnquist, Norman Grogin, Yicheng Guo, Christopher J. Conselice, L. Y. Aaron Yung, Kalina Nedkova, Bahram Mobasher, Ray A. Lucas, Vihang Mehta, Y. Sophia Dai, Jonathan P. Gardner

Publications and Research

Understanding the complicated processes that regulate star formation and cause a galaxy to become quiescent is key to our comprehension of galaxy evolution. We used eight well-resolved star-forming z < 0.3 galaxies from the UVCANDELS survey, where a total of 10 Hubble Space Telescope bands, including UV follow-up in UVIS/F275W, allow us to reconstruct the star formation histories (SFHs) of regions across each galaxy. This approach provides a powerful tool to explore the spatiotemporal connection between star formation and galaxy evolution. The spatial and temporal profiles of stellar mass and star formation rate (SFR) surface density were obtained from the SFHs of these regions. We measure scaling relations and projected radial profiles of regions within each galaxy at the time of observation and at 1 Gyr lookback time, noting possible trends in the evolution. By comparing the change in star formation over time, we can infer the timing and location of star formation and see early signs of star formation shutting off before quenching occurs. We compared the SFR density–stellar mass density scaling relations for individual galaxies as they evolve from 1 Gyr lookback time. The correlation lines pivot around a log-stellar mass surface density of 7.25 [M⊙ kpc−2], which may be evidence of a self-regulating process on these scales. Radial profiles of the galaxy logarithmic specific SFR (sSFR) show an overall decrease over 1 Gyr, but five galaxies show a greater change in log(sSFR) at the outskirts than the center, indicating a possible early onset of quenching in these galaxies.

Antimicrobial Performance Of Amorphous Vs. Crystalline La1-Xsrxcoo3 Perovskites, S. M. Au Shohag, Fahmida Akhter, Ahmed Touhami, Swati Mohan, Md. Wasikur Rahman, Mohammed Jasim Uddin

Physics & Astronomy Faculty Publications

Perovskite materials, with their unique crystal structure and chemical properties, are emerging as promising antimicrobial agents for potential biomedical applications. In this research, different weight percentages of Sr2 + doped amorphous and crystalline Lanthanum Cobaltite (La1-xSrxCoO3 defined as LSCO) (x = 0, 0.025, 0.05, 0.1, and 0.15) perovskite was synthesized by using a simple combination of sol-gel and molten-salt processes and characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM) ensures the uniform morphology of the materials. During antimicrobial study using the Kirby Bauer method, amorphous LSCO showed much better activity than crystalline LSCO against Escherichia coli, Vibrio …

Discovery Of A New Cataclysmic Variable, Galex J211240.9–422959, Via The Exoasteroids Citizen Science Project, Mei Lin, Aaron Meisner, Siyi Xu, Arttu Sainio, Liliana E. Rivera Sandoval, Paula Szkody, Christopher Tanner, Laura K. Rogers, Sarah Casewell, Austin Humphreys

Physics & Astronomy Faculty Publications

We report the discovery and spectroscopic classification of a new cataclysmic variable (CV), GALEX J211240.9–422959 (Gaia DR3 source ID 6580244356829724928). This object was initially identified as a source exhibiting strong mid-infrared variability in Wide-field Infrared Survey Explorer (WISE) time-series data by a volunteer participating in the Exoasteroids citizen science project. Prompted by this strong variability at 3–5 μm, we obtained a follow-up optical spectrum using the Gemini Multi-Object Spectrograph at the Gemini South Observatory. The resulting spectrum displays a blue continuum dominated by strong, broad emission lines of the hydrogen Balmer series and neutral helium, spectral signatures characteristic of …

A Search For Magnetically Active Binary Counterparts To Chandra X-Ray Sources In 47 Tucanae With Hst Imaging, Haldan N. Cohn, Phyllis M. Lugger, Craig O. Heinke, Maureen Van Den Berg, Liliana Rivera Sandoval, Jay Anderson

Physics & Astronomy Faculty Publications

Using Hubble Space Telescope (HST) imaging, we searched for candidate magnetically active binary (AB) counterparts to low-luminosity Chandra X-ray sources in the globular cluster 47 Tucanae (NGC 104). We consider the catalog of 300 Chandra sources within the half-light radius of 47 Tuc compiled by C. O. Heinke et al. (2005). The 10-band HST imaging used to identify these sources spans the range from 275–658 nm. We generated a cross-matched catalog of objects detected by photometric reductions. We used this catalog to search for counterparts within Chandra source error circles using color–magnitude diagrams and a color–color plot. We …

Inferring The Breakdown Scales Of The Chiral Expansions For GA And MN, Andreas Ekström, Daniel R. Phillips, Lucas Platter, Matthias Schindler

Faculty Publications

We apply Bayesian inference to the order-by-order chiral perturbation theory (χPT) expansions for the axial-vector coupling constant g_A and the nucleon mass m_N, and thereby infer the scales at which χPT breaks down for these two observables. Using a pointwise Bayesian analysis, we find that the inferred breakdown scales are notably different for the two observables. For the chiral expansion of g_A, we obtain 251⁺²⁰₋₅₀ MeV and 211⁺²⁰₋₃₀ MeV using two distinct sets of low-energy constants, while for the chiral expansion of m_N we infer a significantly …

Measuring The Flux Of Cosmic Ray Muons With A Coincidence Telescope, Carlos C. Sifuentes

Posters - 2026

❖ Cosmic Ray Muons are short-lived fundamental particles formed in the upper atmosphere, and have a half-life of 2.2 microseconds.[3] They travel down to surface level due to relativistic effects.

❖ Cosmic Watch Muon detectors were placed in coincidence. [1]

❖ Varied the angle from zenith using a 3D printed telescope designed in AutoCad.

❖ Varied the distance of the detectors and viewed changes in flux

Step By Step Progress Told On Florence State Building, Florence Times-Florence Astronomy Society

Documents

News article from the Florence Astronomy Society about the progress of the new Planetarium and Observatory for Florence State College.

10 Men Construct, Donate Florence State's Telescope, Florence Picture

Documents

News article focusing on the 10 men who built the telescope for the Florence State College Observatory. These men were a part of the Florence Astronomy Society and built this telescope to donate to the university.

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.

Florence State University Planetarium-Observatory Information And Schedule, Florence Herald Offset

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Florence State University Planetarium & Observatory Information and Schedule Brochure for Academic Year 1970-1971