Publications (34)
Masses, Revised Radii, and a Third Planet Candidate in the "Inverted" Planetary System Around TOI-1266
Ryan Cloutier, Michael Greklek-McKeon, Serena Wurmser +40
Is the population of close-in planets orbiting M dwarfs sculpted by thermally driven escape or is it a direct outcome of the planet formation process? A number of recent empirical…
Free Floating or Merely Detached?
Sam Hadden, Yanqin Wu
Microlensing surveys suggest the presence of a surprisingly large population of free-floating planets, with a rate of about two Neptunes per star. The origin of such objects is not…
The Criterion for Chaos in Three-Planet Systems
Jeremy Rath, Sam Hadden, Yoram Lithwick
We establish the criterion for chaos in three-planet systems, for systems similar to those discovered by the Kepler spacecraft. Our main results are as follows: (i) The simplest cr…
The Persistent Missing Mass Problem in Planet Formation
Eve J. Lee, William DeRocco, Sam Hadden +1
Recent ground-based microlensing surveys suggest that our Galaxy may abound with small free floating planets, potentially up to 21 such planets per star. We explore the impli…
A Compact Multi-Planet System With A Significantly Misaligned Ultra Short Period Planet
Joseph E. Rodriguez, Juliette C. Becker, Jason D. Eastman +20
We report the discovery of a compact multi-planet system orbiting the relatively nearby (78pc) and bright () K-star, K2-266 (EPIC248435473). We identify up to six possible p…
Chaotic Dynamics of Trans-Neptunian Objects Perturbed by Planet Nine
Sam Hadden, Gongjie Li, Matthew J. Payne +1
Observations of clustering among the orbits of the most distant trans-Neptunian objects (TNOs) has inspired interest in the possibility of an undiscovered ninth planet lurking in t…
Stepsize errors in the -body problem: discerning Mercury's true possible long-term orbits
David M. Hernandez, Richard E. Zeebe, Sam Hadden
Numerical integrations of the Solar System have been carried out for decades. Their results have been used, for example, to determine whether the Solar System is chaotic, whether M…
Intra-system uniformity: a natural outcome of dynamical sculpting
Caleb Lammers, Sam Hadden, Norman Murray
There is evidence that exoplanet systems display intra-system uniformity in mass, radius, and orbital spacing (like ``peas in a pod'') when compared with the system-to-system varia…
An Integrable Model for the Dynamics of Planetary Mean Motion Resonances
Sam Hadden
I consider the dynamics of mean motion resonances between pairs of co-planar planets and derive a new integrable Hamiltonian model for planets' resonant motion. The new model gener…
Rattle-and-Break: the Impact of Planetesimal Scattering on Super-Earth Resonant Chains
Sam Hadden, Yanqin Wu
The spacings of super-Earths in multi-transiting systems exhibit a distribution that is broad and mostly featureless, with the exception of notable excesses of planet pairs situate…
The instability mechanism of compact multiplanet systems
Caleb Lammers, Sam Hadden, Norman Murray
To improve our understanding of orbital instabilities in compact planetary systems, we compare suites of -body simulations against numerical integrations of simplified dynamical…
The Gold Standard: Accurate Stellar and Planetary Parameters for Eight Kepler M dwarf Systems Enabled by Parallaxes
Andrew W. Mann, Trent Dupuy, Philip S. Muirhead +6
We report parallaxes and proper motions from the Hawaii Infrared Parallax Program for eight nearby M dwarf stars with transiting exoplanets discovered by Kepler. We combine our dir…
Accelerating Giant Impact Simulations with Machine Learning
Caleb Lammers, Miles Cranmer, Sam Hadden +3
Constraining planet formation models based on the observed exoplanet population requires generating large samples of synthetic planetary systems, which can be computationally prohi…
Mildly-Hierarchical triple dynamics and applications to the outer solar system
Hareesh Gautham Bhaskar, Gongjie Li, Sam Hadden +2
Three-body interactions are ubiquitous in astrophysics. For instance, Kozai-Lidov oscillations in hierarchical triple systems have been studied extensively and applied to a wide ra…
celmech: A Python package for celestial mechanics
Sam Hadden, Daniel Tamayo
We present celmech, an open-source Python package designed to facilitate a wide variety of celestial mechanics calculations. The package allows users to formulate and integrate equ…
Modeling Radial Velocity Data of Resonant Planets to Infer Migration Histories
Sam Hadden, Matthew J. Payne
A number of giant planet pairs discovered by the radial velocity method with period ratios may reside in mean motion resonances. Convergent orbital migration and reson…
Mercury's chaotic secular evolution as a subdiffusive process
Dorian S. Abbot, Robert J. Webber, David M. Hernandez +2
Mercury's orbit can destabilize, generally resulting in a collision with either Venus or the Sun. Chaotic evolution can cause g1 to decrease to the approximately constant value of…
Scattered Disk Dynamics: The Mapping Approach
Sam Hadden, Scott Tremaine
We derive, and discuss the properties of, a symplectic map for the dynamics of bodies on nearly parabolic orbits. The orbits are perturbed by a planet on a circular, coplanar orbit…
Numerical and Analytical Modelling of Transit Time Variations
Sam Hadden, Yoram Lithwick
We develop and apply methods to extract planet masses and eccentricities from observed transit time variations (TTVs). First, we derive simple analytic expressions for the TTV that…
Densities and Eccentricities of 139 Kepler Planets from Transit Time Variations
Sam Hadden, Yoram Lithwick
We extract densities and eccentricities of 139 sub-Jovian planets by analyzing transit time variations (TTVs) obtained by the Kepler mission through Quarter 12. We partially circum…
Simple physics and integrators accurately reproduce Mercury instability statistics
Dorian S. Abbot, David M. Hernandez, Sam Hadden +3
The long-term stability of the Solar System is an issue of significant scientific and philosophical interest. The mechanism leading to instability is Mercury's eccentricity being p…
Near-resonance in a system of sub-Neptunes from TESS
Samuel N. Quinn, Juliette C. Becker, Joseph E. Rodriguez +78
We report the Transiting Exoplanet Survey Satellite () detection of a multi-planet system orbiting the K0 dwarf TOI 125. We find evidence for up to five planets, wit…
Influence of Modeling Assumptions on the Inferred Dynamical State of Resonant Systems: A Case Study of the HD 45364 System
Ian Chow, Sam Hadden
Planetary systems exhibiting mean-motion resonances (MMRs) offer unique opportunities to study the imprint of disk-induced migration on the orbital architectures of planetary syste…
Rare Event Sampling Improves Mercury Instability Statistics
Dorian S. Abbot, Robert J. Webber, Sam Hadden +2
Due to the chaotic nature of planetary dynamics, there is a non-zero probability that Mercury's orbit will become unstable in the future. Previous efforts have estimated the probab…
Action-Angle Variables for Axisymmetric Potentials via Birkhoff Normalization
Sam Hadden
We describe a method for calculating action-angle variables in axisymmetric galactic potentials using Birkhoff normalization, a technique from Hamiltonian perturbation theory. An a…
Are long-term -body simulations reliable?
David M. Hernandez, Sam Hadden, Junichiro Makino
-body integrations are used to model a wide range of astrophysical dynamics, but they suffer from errors which make their orbits diverge exponentially in time from the correct o…
Prospects for TTV Detection and Dynamical Constraints with TESS
Sam Hadden, Thomas Barclay, Matthew J. Payne +1
We consider the potential for the Transiting Exoplanet Survey Satellite (TESS) to detect transit timing variations (TTVs) during both its nominal and extended mission phases. Build…
Prospects for Refining Kepler TTV Masses using TESS Observations
Max Goldberg, Sam Hadden, Matthew J. Payne +1
In this paper we investigate systems previously identified to exhibit transit timing variations (TTVs) in Kepler data, with the goal of predicting the expected improvements to the…
Eccentricities of Close Stellar Binaries
Yanqin Wu, Sam Hadden, Janosz Dewberry +2
Orbits of stellar binaries are in general eccentric. These eccentricities encode information about their early lives. Here, we use thousands of main-sequence binaries from the Gaia…
Self-Consistent Spin, Tidal and Dynamical Equations of Motion in the REBOUNDx Framework
Tiger Lu, Hanno Rein, Daniel Tamayo +4
We have introduced self-consistent spin, tidal and dynamical equations of motion into REBOUNDx, a library of additional effects for the popular N-body integrator REBOUND. The equat…
The Effects of Disk Induced Apsidal Precession on Planets Captured into Mean Motion Resonance
Zachary Murray, Sam Hadden, Matthew J. Holman
The process of migration into resonance capture has been well studied for planetary systems where the gravitational potential is generated exclusively by the star and planets. Howe…
A Criterion for the Onset of Chaos in Systems of Two Eccentric Planets
Sam Hadden, Yoram Lithwick
We derive a criterion for the onset of chaos in systems consisting of two massive, eccentric, coplanar planets. Given the planets' masses and separation, the criterion predicts the…
Significant improvement in planetary system simulations from statistical averaging
David M. Hernandez, Eric Agol, Matthew J. Holman +1
Symplectic integrators are widely used for the study of planetary dynamics and other -body problems. In a study of the outer Solar system, we demonstrate that individual symplec…
Kepler Planet Masses and Eccentricities from TTV Analysis
Sam Hadden, Yoram Lithwick
We conduct a uniform analysis of the transit timing variations (TTVs) of 145 planets from 55 Kepler multiplanet systems to infer planet masses and eccentricities. Eighty of these p…