Daohai LI

Hello, I am Daohai LI, a postdoctoral research fellow working at Lund Observatory, working on, in general, planetary dynamics, in collaboration with Doctor Alexander James Mustill, Professor Melvyn B. Davies and Professor Anders Johansen. Before joining Lund, I was doing my PhD study with Dr Apostolos A. Christou at the Armagh Observatory and Queen's University Belfast. I got my MSc at Nanjing University and BSc at Beijing Normal University, working with Prof Ji-Lin ZHOU and Biwei JIANG, respectively.

My email addresses are "li.daohai'at'astro.lu.se" and "idaohai'at'gmail.com". My work address is
Office 248,
Lund Observatory,
Department of Astronomy and Theoretical Physics, Lund University,
Box 43, SE-221 00 Lund, Sweden.

Encounter between planetary systems

In this project, we investigate the close encounters between two solar systems. On the left is an illustration.

Origin of Neptunian moons Triton and Nereid

On the left are images of the neptunian moons Triton (bottom; credit: NASA/JPL/USGS) and Nereid (top; credit: NASA/JPL) taken by NASA's Voyager 2 spacecraft. The two have peculiar orbits among all solar system moons. We explain the origin of the peculiarity by invoking a planetary encounter.

The Himalia satellite family

On the left is an image of Himalia taken by NASA's Cassini spacecraft; credit: NASA/JPL/University of Arizona. We develop models to study the dynamical original of the widespread of this irregular satellite family.

Circumbinary orbits

In this project, we study the classical restricted three-body problem, i.e., the evolution of a massless particle under the gravitational potential of a pair of two massive objects.

Short CV

See my CV below; kindly let me know if you are interested in more details.


  • 2018-06--2021-05 Postdoctoral research fellow, Lund University, Lund, Sweden
  • 2018-01--2018-05 Research Associate, Armagh Observatory and Planetarium, Armagh, UK


  • 2014-10--2017-12 PhD in Astronomy, Armagh Observatory and Planetarium and Queen's University Belfast, UK
  • 2011-09--2014-07 MSc in Astrometry and Celestial Mechanics, Nanjing University, China
  • 2007-09--2011-07 BSc in Astronomy, Beijing Normal University, China


  1. Li, D., Johansen, J., Mustill, A. J., Davies, M. B. & Christou, A. A., 2020, Capture of satellites during planetary encounters A case study of the Neptunian moons Triton and Nereid, A&A, in press
  2. Li, D., Mustill, A. J. & Davies, M. B., 2020, Fly-by encounters between two planetary systems II: Exploring the interactions of diverse planetary system architectures, MNRAS, in press
  3. Li, D. & Christou, A. A., 2020, The origin of Neptune's unusual satellites from a planetary encounter, AJ, 159, 184
  4. Li, D., Mustill, A. J. & Davies, M. B., 2019, Fly-by encounters between two planetary systems I: Solar system analogues, MNRAS, 488, 1366
  5. Li, D. & Christou, A. A., 2018, Long-term self-modification of irregular satellite groups, Icarus, 310, 77
  6. Li, D. & Christou, A. A., 2017, Orbital modification of the Himalia family during an early solar system dynamical instability, AJ, 145, 209
  7. Li, D. & Christou, A. A., 2017, Secular resonances between bodies on close orbits II: prograde and retrograde orbits for irregular satellites, CeMDA, 129, 1
  8. Li, D. & Christou, A. A., 2016, Secular resonances between bodies on close orbits: a case study of the Himalia prograde group of jovian irregular satellites, CeMDA, 125, 133
  9. Li, D., Zhou, J.-L. & Zhang, H., 2014, Analytical theories for near coplanar and polar circumbinary orbits, MNRAS, 437, 3832


Besides work, I regularly swim and play ping-pong.