Academic CV

Contact emails:
NASA*: matthias.y.he (at) nasa.gov
SETI: mhe (at) seti.org
Personal: matthias.he (at) alumni.utoronto.ca

*Note: this is firewalled and not all content may get through.

Positions

NASA Postdoctoral Program (NPP) Fellow → SETI Postdoctoral Researcher, NASA Ames Research Center
2024 - Present
Advisors: Dr. Steve Bryson, Dr. Jon Jenkins, Dr. Douglas Caldwell

Postdoctoral Research Associate, University of Notre Dame
2022 - 2024
Advisor: Prof. Lauren M. Weiss

Education

Ph.D. in Astronomy & Astrophysics, Pennsylvania State University
Graduate minor in Computational Science
2016 - 2022
Advisor: Prof. Eric B. Ford
Dissertation: Statistical Inference on the Distribution of Exoplanetary Systems: Correlations in Planetary System Architectures

Honours B.Sc. - Astronomy & Physics Specialist, University of Toronto
High Distinction
2012 - 2016
Advisor: Prof. Dae-Sik Moon

To view my full academic CV, click here (last updated May 22, 2026).

Publications

• Architectures of Exoplanetary Systems. IV: A Multi-planet Model for Reproducing the Radius Valley and Intra-system Size Similarity of Planets around Kepler’s FGK Dwarfs
  Matthias Y. He, Eric B. Ford, 2026, ApJ, 1001, 78-112

• Why Estimating η⊕ is Difficult: A Kepler-Centric Perspective
  Steve Bryson, Michelle Kunimoto, Ruslan Belikov, incl. Matthias Y. He, 2025, PASP, 137, 124401, 21pp

• Are We There Yet? Challenges in Quantifying the Frequency of Earth Analogs in the Habitable Zone
  Rachel B. Fernandes, Samson Johnson, Galen J. Bergsten, incl. Matthias Y. He (lead authors), 2025, PASP, 137, 121001, 28pp

• Biases from Missing a Small Planet in High Multiplicity Systems
  Alexander C. Thomas, Lauren M. Weiss, Matthias Y. He, 2025, ApJL, 984, L30-39

• Developing a Drift Rate Distribution for Technosignature Searches of Exoplanets
  Megan G. Li, Sofia Z. Sheikh, Christian Gilbertson, Matthias Y. He, Howard Isaacson, Steve Croft, Evan L. Sneed, 2023, AJ, 166, 182-192

• Beyond 2-D Mass-Radius Relationships: A Nonparametric and Probabilistic Framework for Characterizing Planetary Samples in Higher Dimensions
  Shubham Kanodia, Matthias Y. He, Eric B. Ford, Sujit K. Ghosh, Angie Wolfgang, 2023, AJ, 956, 76-89
  arXiv link: 2308.10615
  Github repository: MRExo

• Inner Planetary System Gap Complexity is a Predictor of Outer Giant Planets
  Matthias Y. He, Lauren M. Weiss, 2023, AJ, 166, 36-48
  arXiv link: 2306.08846
  Press: Universe Today article on our paper

• Debiasing the Minimum-Mass Extrasolar Nebula: On the Diversity of Solid Disk Profiles
  Matthias Y. He, Eric B. Ford, 2022, AJ, 164, 210-220
  arXiv link: 2208.09031

• Edge-of-the-Multis: Evidence for a Transition in the Outer Architectures of Compact Multiplanet Systems
  Sarah C. Millholland, Matthias Y. He, Jon K. Zink, 2022, AJ, 164, 72-87
  arXiv link: 2207.10068

• Friends and Foes: Conditional Occurrence Rates of Exoplanet Companions and their Impact on Radial Velocity Follow-up Surveys
  Matthias Y. He, Eric B. Ford, Darin Ragozzine, 2021b, AJ, 162, 216-238
  arXiv link: 2105.04703

• Evidence for a Non-Dichotomous Solution to the Kepler Dichotomy: Mutual Inclinations of Kepler Planetary Systems from Transit Duration Variations
  Sarah C. Millholland, Matthias Y. He, Eric B. Ford, Darin Ragozzine, Daniel Fabrycky, Joshua N. Winn, 2021, AJ, 162, 166-183
  arXiv link: 2106.15589

• Architectures of Exoplanetary Systems. III: Eccentricity and Mutual Inclination Distributions of AMD-stable Planetary Systems
  Matthias Y. He, Eric B. Ford, Darin Ragozzine, Daniel Carrera, 2020, AJ, 160, 276-314
  arXiv link: 2007.14473
  Press Release: Penn State ICDS News article on our paper
  Github repository: SysSimExClusters (He_et_al_2020b branch)

• Architectures of Exoplanetary Systems. II: An Increase in Inner Planetary System Occurrence Towards Later Spectral Types for Kepler’s FGK Dwarfs
  Matthias Y. He, Eric B. Ford, Darin Ragozzine, 2021a, AJ, 161, 16-40
  arXiv link: 2003.04348
  Github repository: SysSimExClusters (He_Ford_Ragozzine_2020 branch)

• Architectures of Exoplanetary Systems. I: A Clustered Forward Model for Exoplanetary Systems around Kepler’s FGK Stars
  Matthias Y. He, Eric B. Ford, Darin Ragozzine, 2019, MNRAS, 490, 4575-4605
  arXiv link: 1907:07773
  Github repository: SysSimExClusters (He_Ford_Ragozzine_2019 branch)

• On the stability and collisions in triple stellar systems
  Matthias Y. He and Cristobal Petrovich, 2018, MNRAS, 474, 20-31

• First limits on the occurrence rate of short-period planets orbiting brown dwarfs
  Matthias Y. He, Amaury H.M.J. Triaud, Michael Gillon, 2017, MNRAS, 464, 2687-2697

• KMTNet Supernova Program Variable Objects I. NGC 2784 Field
  Matthias Y. He, Dae-Sik Moon, Hilding Neilson, Jae-Joon Lee, Sang Chul Kim, Mina Park, Hong Soo Park, Dong-Jin Kim, Yongseok Lee, Seung-Lee Kim, Chung-Uk Lee, 2016, JKAS, 49, 209-233

• Supernova and optical transient observations using the three wide-field telescope array of the KMTNet
  Dae-Sik Moon, Sang Chul Kim, Jae-Joon Lee, Mina Pak, Hong Soo Park, Matthias Y. He, John Antoniadis, Yuan Qi Ni, Chung-Uk Lee, Seung-Lee Kim, Byeong-Gon Park, Dong-Jin Kim, Sang-Mok Cha, Yongseok Lee, Santiago Gonzalez, 2016, Proc. SPIE 9906

Software Packages

• MRExo
  Language: Python 3
  Developers: Shubham Kanodia, Matthias Y. He

• SysSimPyMMEN
  Language: Python 3
  Developers: Matthias Y. He

• SysSimPyPlots
  Language: Python 3
  Developers: Matthias Y. He

• SysSimExClusters
  Language: Julia
  Developers: Matthias Y. He, Eric B. Ford

• ExoplanetsSysSim
  Language: Julia
  Developers: Eric B. Ford, Matthias Y. He, Danley Hsu, Darin Ragozzine

Conferences and Presentations

• AAS 247 - Talk (Jan 8, 2026 - Phoenix, AZ)

• Origins Seminar - Talk (Nov 24, 2025 - UArizona)

• NPP Virtual Symposium - Talk (Nov 20, 2025 - Virtual)

• Sagan Summer Workshop 2025 - Poster (Jul 21-25, 2025 - Caltech)

• CCA Exoplanet Meeting - Talk (Jun 26, 2025 - Flatiron Institute)

• Exoplanet Dynamics & Modeling - Talk (Mar 11-14, 2025 - Caltech)

• AAS 245 - iPosters (Jan 12-16, 2025 - National Harbor, MD)

• Ames HWO Meeting - Talk (with Aritra Chakrabarty) (Aug 26, 2024 - NASA Ames)

• GLEAM 2023 - Talk (Oct 27-28, 2023 - IU Bloomington)

• Postdoc Lightning Talk Competition, 2nd place finish - 3min Talk (Sep 21, 2023 - Notre Dame)

• Astrophysics Seminar - Talk (Sep 19, 2023 - Notre Dame)

• IU Tea Talk - Talk (Sep 11, 2023 - IU Bloomington)

• Protostars and Planets VII - Poster (Apr 10-15, 2023 - Kyoto, Japan)

• COSE-JAM - Poster (Dec 9, 2022 - Notre Dame)

• GLEAM 2022 - Talk (Nov 17-18, 2022 - Ohio State)

• Penn State Dissertation Defense - Thesis Talk (recording on exoplanet-talks.org!) (Feb 15, 2022 - Virtual)

• ERES VII - Poster (Aug 1-2, 2022 - Penn State)

• DDA 53rd - Poster (Apr 25-28, 2022 - Flatiron Institute)

• Center for Space and Habitability (CSH) Fellowship - Talk (Feb 2, 2022 - Virtual)

• BAEM 39 - Talk (Dec 3, 2021 - Virtual)

• UChicago Exoplanet Group - Talk (Oct 18, 2021 - Virtual)

• ERES VI - Poster (May 24-26, 2021 - Virtual)

• CHEXO - Talk (May 14, 2021 - Virtual)

• PLATO ESP 2020 - Talk (Dec 3, 2020 - Virtual)

• Exoplanet Demographics 2020 - Talk (Nov 11, 2020 - Virtual)

• EPSC 2020 - Talk (Sep 24, 2020 - Virtual)

• CEHW Seminar - Talk (Sep 14, 2020 - Virtual)

• DDA 51st - Talk (August 3, 2020 - Virtual)

• Exoplanets III - Plenary Talk (July 29, 2020 - Virtual)

• CHEXO - Talk (June 26, 2020 - Virtual)

• AAS 236 - iPoster (June 1-3, 2020 - Virtual)

• NASA ExoPAG 21 - Talk (Jan 4, 2020 - Honolulu, HI)
  Also served on a discussion panel of Kepler reliability

• Lunch Talk - Talk (Sep 17, 2019 - Penn State)

• Extreme Solar Systems IV - Talk (Aug 20, 2019 - Reykjavik, Iceland)

• TESS Science Conference I - Poster (Jul 29 - Aug 2, 2019 - MIT)

• Stars and Planets Seminar - Talk (Jul 19, 2019 - CITA/U of T)

• ERES V - Talk (Jun 17, 2019 - Cornell)

• ICS Symposium - Poster (Apr 1, 2019 - Penn State)

• SMAC Talk - Talk (Mar 22, 2019 - Penn State, Dept. of Statistics)

• ERES IV - Talk (Jun 22, 2018 - Penn State)

• Lunch Talk - Talk (Jan 16, 2018 - Penn State)

• ERES III - Talk (Jun 13, 2017 - Yale)

• SAMSI Transition Workshop - Poster (May 9, 2017 - Durham, NC)

• SURP student presentations - Talk (Jul 7, 2016 - CITA/U of T)