My name is Fei Dai (戴飞). I'm a NASA Sagan fellow in the Division of Physics, Mathematics, and Astronomy at Caltech. Previously I obtained my PhD in Physics from MIT under the supervision of Prof. Josh Winn.

Using both novel data analysis techniques and numerical simulations, I strive to understand the formation, evolution, and habitability of planetary systems. In particular, I focus on the most extreme planetary systems that look nothing like our Solar System including the "ultra-short-periods", the "super-puffs", planetary systems locked deep in resonance, and planetary systems dynamically tilted to polar orbits around their host stars.

Picture on the right was taken at Salar de Uyuni, Bolivia.

Research Highlights

  • Planetary Systems locked in a chain of mean-motion resonances likely produced by disk migration.

  • The Ultra-Short-Period: hellish worlds that orbit their host stars with periods as short as a few hours.

  • Puzzling low-density planets that should not exist.

  • Exotic Planets that orbit their host stars on polar or even retrograde orbits.

  • Starspots leave photometric signatures in planetary transit light curves which can unveil the orbital orientation and magnetic activity.

  • We extended the study of planet radius distribution (Fulton et al 2018) from Sun-like stars to M-dwarf planets. Results suggests that photoevaporation rather than core-powered mass loss is the main driver for the observed radius gap.

  • We studied the process of hydrodynamic atmospheric erosion with 3-D self-consistent simulations.

  • K2, the second phase of the NASA Kepler mission, enabled us to discover many exciting planetary systems along the ecliptic.

  • A pair of young stars that likely underwent a close encounter: a scenario that is supported by optical dimming, the tidal arms, and a strong Fe emission in X-ray.

  • Image credits: NASA/JPL-Caltech/T. Pyle, ESO/L. Calcada, Kley & Nelson, AAS Nova, Addison, Sanchis-Ojeda, Fulton, Haworth.


  • 111 All Publications
  • 13 First-Authored
  • 2548 Citations
  • 31 h-index
  • 68 i10-index

More up-to-date publication lists can be found here:

Community Service and Outreach

  • A free online workshop for undergraduate students aspiring to become an astronomer.

  • Check out some public talks I gave recently both in English and Mandarin Chinese.

  • I am a mentor for the Caltech WAVE Program: an undergraduate research program for underrepresented minority students.

Brief Bio

I was a graduate student at MIT Department of Physics from 2014 to 2019. I was also a visiting student at Princeton Univerity (2017-2019). Previously, I received B.A. in Natural Science and M.Sci in Physics from the University of Cambridge in 2014 with First Class Honours.