About Me
Education: Ph.D. Astronomy, Cornell University (2024); M.S. Astronomy, Cornell University (2020);
B.S. Astrophysics, University of California, Los Angeles (2018)
Research Interests:
Theoretical astrophysics, including astrophysical dynamics,
stellar and planetary astrophysics, compact objects, dense star clusters, Milky Way Galactic Center.
Observational exoplanet science, especially for systems around evolved stars and white dwarfs.
Nonlinear dynamics and chaos, with applications to astrophysical systems.
Publications: ADS
Research
Dynamics of dense star clusters.
At CIERA, I've been studying the evolution of dense star clusters with the Cluster Monte Carlo (CMC) code.
My current focus is on constraining the outcomes of star formation in dense clusters by studying the evolution of clusters
with different initial mass functions and primordial binary populations.
Papers on this topic are in preparation.
Planet engulfment events.
Close-in planets are common around Sun-like stars, and some unlucky planets get engulfed and destroyed over their host star's lifetime.
This can happen either as the star swells into a red giant after exhausting its core hydrogen supply
or through dynamical interactions between planets while the star is still on the main sequence.
I'm interested in both of these scenarios.
Modeling planet engulfment events with MESA - O'Connor et al. (2023)
Ultra-short-period planet engulfment by Sun-like stars - O'Connor & Lai 2025
Dynamical origins of white-dwarf pollution.
More than 1/3 of white-dwarf stars are constantly ingesting debris from tidally disrupted planetary bodies previously
in orbit around these stellar remnants. This "pollution" offers a unique window into the final stage in the life cycle
of a planetary system, particularly from the perspective of long-term dynamical evolution. I'm interested in
applying dynamical theory to understand the processes by which planetary debris is delivered to a white dwarf.
White dwarf pollution from secular chaos - O'Connor, Teyssandier & Lai (2022)
Why don't we observe white-dwarf pollution from exocomets? - O'Connor, Lai & Seligman (2023)
Tidal interactions and high-e migration in planetary and stellar systems.
Many forms of dynamical evolution in astrophysical systems lead to close encounters between a planet and
a star or between two stars. At these close distances, tidal forces between the objects lead to a variety of
interesting phenomena, ranging from the excitation of a body's internal oscillations -- in essence, making it
ring like a bell -- to tearing it apart entirely. Nature seems to produce all of these outcomes in different settings.
I've studied high-eccentricity migration in a few different papers so far, mostly in relation to surviving planetary
systems around white dwarfs.
High-e migration of a Jupiter-sized planet in orbit around a white dwarf - O'Connor, Liu & Lai (2021)
Migration of asteroids around white dwarfs - O'Connor & Lai (2020)
Constraining tidal dissipation with Hot Jupiters in star clusters - O'Connor & Hansen (2018)
Service & Teaching
Coming soon...
Contact
Email: christopher ~dot~ oconnor [at] northwestern *dot* edu
Address: CIERA, Northwestern University, 1800 Sherman Ave 8th Floor, Evanston, IL 60201
