Roles and responsibilities

Assistant Research Officer (Plaskett Fellow)

I am an observational planetary astronomer. Using optical and near-infrared observatories, I am interested in studying planets found around other stars (exoplanets). Specifically, I am interested in imaging these exoplanet systems to learn how planets form and how their orbital parameters have evolved since formation. I am also interested in searching for new giant planets through imaging with adaptive optics instruments on large telescopes.

Current research and/or projects

I study the formation and evolution of planets around other stars using Canadian and international observatories, in collaboration with Canadian and international universities.

Research and/or project statements

  • Determining the influence of companion stars on planet formation and evolution
  • Validation of newly discovered Earth-like planet candidates
  • Bayesian orbit fitting of directly imaged planetary and stellar companion candidates
  • Searching for new directly imaged companions to nearby M-dwarf stars
  • Science validation for upgrades to direct imaging and adaptive optics instruments


  • Ph.D. Planetary Science, California Institute of Technology, 2017
  • M.S. Planetary Science, California Institute of Technology, 2014
  • M.Sc. Astronomy, Queen’s University at Kingston, 2012
  • B.Sc. (Hons.) Physics and Astronomy, University of British Columbia, 2010

Professional activities/interests

  • Co-supervisor to several undergraduate and graduate students
  • Referee for astronomical journals
  • NASA Transiting Exoplanet Survey Satellite (TESS) Follow-up Observing Program Working Group Member
  • NASA Exoplanet Policy Analysis Group Member


  • Canadian Astronomical Society (CASCA)
  • American Astronomical Society (AAS)
  • International Astronomical Union (Jr. Member)

Key publications

Reference star differential imaging of close-in companions and circumstellar disks with the NIRC2 vortex coronagraph at W.M. Keck Observatory
G. Ruane, H. Ngo, D. Mawet et al. 2019, Astronomical Journal, 157, 118. DOI:

Characterizing the Performance of the NIRC2 Vortex Coronagraph at W. M. Keck Observatory
W. J. Xuan*, D. Mawet, H. Ngo et al. 2018, Astronomical Journal, 156, 156. DOI:

No difference in orbital parameters of RV-detected giant planets between 0.1-5 au in single vs. multi-stellar systems
H. Ngo, H. Knutson, M. Bryan et al. 2017, Astronomical Journal, 153, 242. DOI:

Friends of Hot Jupiters. IV. Stellar companions beyond 50 AU might facilitate giant planet formation, but most are unlikely to cause Kozai-Lidov migration
H. Ngo, H. Knutson, S. Hinkley et al. 2016, Astrophysical Journal, 827, 8. DOI:

Statistics of Long Period Gas Giant Planets in Known Planetary Systems
M. Bryan, H. Knutson, A. Howard, H. Ngo et al. 2016, Astrophysical Journal, 821, 89. DOI:

Friends of Hot Jupiters III. An Infrared Spectroscopic Search for Low-Mass Stellar Companions
D. Piskorz, H. Knutson, H. Ngo et al. 2015, Astrophysical Journal, 814, 148. DOI:

Friends of Hot Jupiters. II. No correspondence Between hot-Jupiter spin-orbit misalignment and the incidence of directly imaged stellar companions
H. Ngo, H. Knutson, S. Hinkley et al. 2015, Astrophysical Journal, 800, 138. DOI:

Friends of Hot Jupiters. I. A Radial Velocity Search for Massive, Long-Period Companions to Close-In Gas Giant Planets
H. Knutson, B. Fulton, B. Montet, M. Kao, H. Ngo et al. 2014, Astrophysical Journal, 785, 126. DOI:

Production of Near-Earth Asteroids on Retrograde Orbits
S. Greenstreet, B. Gladman, H. Ngo et al. 2012, Astrophysical Journal Letters, 749, L39. DOI:

The Orbital Distribution of Near-Earth Objects Inside Earth's Orbit
S. Greenstreet, H. Ngo, and B. Gladman 2012, Icarus, 217, 355. DOI:

Previous work experience

July, 2017 — present
NRC Herzberg Astronomy & Astrophysics Research Centre
Assistant Research Officer (Plaskett Fellowship)

October, 2012 — June, 2017
California Institute of Technology
Graduate Research Assistant

September, 2010 — August, 2012
Queen’s University at Kingston
Graduate Research Assistant

Henry Ngo

Henry Ngo

RA, Optical Astronomy Program
Herzberg Astronomy and Astrophysics
5071 West Saanich Road
Victoria, British Columbia V9E 2E7
Preferred language: English
Telephone: 250-363-6916

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Space sciences, Astronomy, Observational astronomy, Physics, Sciences