Research

First authored publications and primary ongoing research projects

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Classical Cases of Non-Solar Mixing Length in Low Mass Stars

We used geometric radii to constrain the mixing length in detached eclipsing binaries and stars with interferometrically measured diameters, testing literature prescriptions that go beyond a fixed, solar-calibrated mixing length parameter. Other than magnetically inflated fast rotators we found no population level trends for the mixing lengths in eclipsing binaries, calling into question the existence of a ubiquitous calibration beyond the Sun. The mixing length in the interferometric sample on the other hand displayed a strong dependence on metallicity, with very metal-poor stars reaching very subsolar mixing lengths. Such a strong metallicity dependence has implications for the absolute age scale of the oldest populations in our Galaxy and its dwarf satellites.

submitted to ApJ, 2026 Sept 10th; arXiv:2609.13384
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The Rapid Formation of the Metal-poor Milky Way

Using isochrone ages for main sequence turn off and subgiant stars observed in the H3 survey we measured the end of star formation in accreted dwarf galaxies that built up the metal poor populations of the Milky Way. With these star formation truncation times we inferred a rapid assembly of the Galactic halo that culminated with the GSE merger 10 Gyr ago, marking the last majorly disruptive merger in the Milky Way's history.

Published January 2025 in The Astrophysical Journal, 2025ApJ...978..152W
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The Age–Metallicity–Specific Orbital Energy Relation for the Milky Way's Globular Cluster System Confirms the Importance of Accretion for Its Formation

We found that the majority of the Milky Way's metal poor globular clusters lie on a common plane in age-metallicity-orbital energy space, with older or more metal rich clusters being more tightly bound to the Galaxy. This correlation is consistent with the hierarchical assembly of the halo; older, metal poor clusters came from the earliest accreted satellite galaxies and were deposited into the Galaxy's potential back when the Milky Way was smaller and less massive. They remained trapped as the Milky Way continued to grow, while more recently accreted satellites disrupt and deposit their clusters at further radii and higher orbital energies.

Published August 2021 in The Astronomical Journal, 2021AJ....162...42W