Phillips Academy Andover, Class of 2027
Henry
Zimmerman
I follow questions wherever they lead.
About
I'm a junior at Phillips Academy who follows questions across fields, whether that means reading merger signatures in stellar pulsation data, writing about democratic backsliding in post-reunification Germany, or asking what it even means to believe something.
My main scientific work is in time-domain astronomy. In OGLE-LMC-CEP-1347, I recovered a non-radial frequency triplet whose spacing implies a rotation period far slower than the orbital period in an already-circularized orbit, a signature inconsistent with tidal locking and consistent with a recent merger disrupting the star's spin.
A parallel thread is asteroid rotation: I am determining the first confirmed synodic period for main-belt asteroid 7605 Cindygraber, coordinating multi-site observations across Chile, Australia, and the Canary Islands using an open-source scheduler I built for the project.
I co-created Believing Belief, a philosophical website and podcast series examining theodicy, divine perfection, and the epistemology of religious faith, developed alongside a classmate for PHR380: Faith and Doubt at Andover. The same instinct that pulls me toward hard scientific questions pulls me toward hard philosophical ones.
Outside research, I captain the cross-country team, play jazz guitar, and founded RenewBlue, a campus sustainability initiative. I am drawn to problems that require patience, precision, and a willingness to tear down a model when the data demands it.
The star field behind this page is drawn from the Yale Bright Star Catalog. Hover to see names; click to open a star in SIMBAD. The pulsing objects are from my own research. My current reading list is at curius.app/henry-zimmerman.
Research
First Asteroseismic Evidence of Merger Origin in a Binary Cepheid
I analyzed six years of OGLE photometry for OGLE-LMC-CEP-1347, a double-overtone binary Cepheid in the Large Magellanic Cloud with the shortest known orbital period in its class (~59 days). Using a custom prewhitening and Light-Time Travel Effect correction pipeline, I recovered a non-radial frequency triplet with spacing Δf ≈ 0.0074 c/d (R² = 0.99), the signature of rotation-induced mode splitting. The implied rotation period of ~135 days is substantially slower than the orbital period in an already-circularized system. Since tidal theory predicts synchronization precedes circularization by orders of magnitude, finding asynchronous rotation in a circular orbit indicates the Cepheid's spin was recently disrupted by a merger. Mode switching among four pulsation modes across the observing baseline provides additional evidence of a transient post-merger thermal state. This constitutes what appears to be the first asteroseismic confirmation of merger origin in a binary Cepheid.
Rotation Period and Taxonomy of 7605 Cindygraber
I am determining the first confirmed synodic rotation period for main-belt asteroid 7605 Cindygraber. I trained machine learning models on the ALCDEF Light Curve Database to predict period convergence requirements, wrote a formal observing proposal supported by this analysis, and am coordinating multi-site photometric observations across four Slooh observatories (G40 Canary Islands, W88 Chile, E62 Australia, I12 Phillips Academy). I am also extracting spectra from diffraction grating images to constrain its taxonomic classification. Observations are scheduled using an open-source Python tool I built for the project: it queries MPC ephemerides, computes per-site astronomical twilight, and models lunar sky brightness via the Krisciunas-Schaefer model. Preparing results for submission to the Minor Planet Bulletin.
Observing Scheduler on GitHubDistance Scale Calibration via U Sagittarii
My first independent research target. I remotely operated the Slooh Chile 432mm telescope over one month, performing multi-band (V−I) differential photometry of the classical Cepheid U Sgr in open cluster M25. Sinusoidal light curve fits confirmed the 6.74-day period (R² = 0.93 V-band, 0.70 I-band). V-band distance calculations yielded 40.8% error versus 1.9% in I-band, a direct demonstration of how interstellar dust preferentially attenuates shorter wavelengths and why extinction corrections are critical for Cepheid distance work. Strong color index correlation (r = 0.85) provided independent evidence for the kappa-mechanism. The project expanded into an investigation of metallicity-dependent corrections to the period-luminosity relation. Next: examining whether U Sgr shows analogous post-merger asteroseismic signatures to those found in CEP-1347.
Writing
Why I'm Not "All In" On the In-Class Onslaught
Opinion piece arguing that mass in-class writing assessments (adopted to counter AI) that curtail the very iterative thinking they aim to protect, drawing on a published study of time constraints and writing quality.
What's at Stake in Greenland?
Analysis of Trump's Arctic ambitions: why Greenland's strategic value is real, why the approach is counterproductive, and how the sovereignty question reshapes precedent for Ukraine and Taiwan.
Germany's Far-Right Comeback: Why You Should Be Worried About the AfD
On the AfD's rise from eurosceptic fringe to Germany's second-largest party: its causes, its geopolitical alignment with Russia and China, and what it means for European cohesion.
Changes in Japan's Labor and Immigration Policy Address Depopulation Concerns
Japan's demographic crisis through the lens of its historically restrictive immigration framework: what the recent policy shifts signal, and whether they go far enough.
Highlights
VLT/ESPRESSO Spectroscopy Proposal, In Progress
Preparing a proposal for time on the Very Large Telescope to obtain a high-S/N spectrum of OGLE-LMC-CEP-1347, in collaboration with Dr. Bogumil Pilecki. The proposed observations would provide direct chemical abundance constraints on the CEP-1347 system, constituting the first spectroscopic follow-up of a dynamically confirmed Cepheid merger candidate.
Believing Belief , Philosophy of Religion
Co-created a podcast series and website examining theodicy, divine perfection, design arguments, and the epistemology of religious faith. Developed with Genie Han for PHR380: Faith and Doubt at Phillips Academy Andover.
245th AAS Meeting, Phoenix
Attended with the Andover Astronomy Research class. Asked Cepheid researchers whether asteroseismology could confirm merger origin observationally; the consensus was that no one had found a system clean enough to test it. Within weeks of returning, I identified OGLE-LMC-CEP-1347 as the right target and began the analysis that became the CEP-1347 paper.
SHAD Canada, University of British Columbia
Designed a mesh reinforcement system to improve ductility and fracture resistance of Arctic ice roads. Derived expected mechanical behavior from composite materials literature and specified a validation protocol (3-point bending, Charpy impact, in-situ cantilever, environmental cycling) to test predictions against physical samples.
Machine Learning, NYU Tandon School of Engineering
Class-best 90% validation accuracy on CIFAR-10 with minimal FLOPs. Applied supervised learning methods to asteroid period convergence prediction and photometric classification.
Cleanhill Partners, Research Intern
Researched sustainable technologies in the industrial heat sector for an energy-transition-focused private equity firm. Produced a report on emerging solutions and presented findings to senior partners.
RenewBlue, Founder and President
Co-founded a campus sustainability initiative. Organized a multi-school climate-tech hackathon, submitted building-grade algae insulation to The Earth Prize (top 100 finalist), and built a functional model of the school's cogeneration plant.
Phillips Academy Andover
Top 5% of class. AP Physics C: Mechanics and E&M, BC Calculus, Advanced College Chemistry, Astronomy Research. Webster Award (History and Social Sciences). Scholastic Art and Writing Silver Key. Cross-Country Captain 2026; personal records 16:30 5km XC, 4:24 1500m. Podium finish at NEPSTA Division I Championship.