Research Field

Home

Summer 2008:

Harvard-Smithsonian Center for Astrophysics

Summer research with Prof. Dimitar Sasselov and the Walsworth Group on Exoplanet and AstroComb Project.

★The first part of my research was on AstroComb. AstroComb is an instrument using a femto-second laser beam and Fabry-Perot Cavity to produce a super-accurate and stable reference spectrum. With AstroComb, we are expecting an accuracy of cm/s in measuring the Doppler shift of stars. This accuracy will allow us to detect the miniscule effect of an Earth-like planet on a Sun-like star. I wrote a program to simulate the output beam profile of the femto-second laser under various pressures and temperatures.

★The second part of my research was on ocean planet detection feasibility through the Kepler mission and the influence of post-perovskite on the mass-radius relation of Super-Earth. We included post-perovskite in our model and the result shows that radius will be inflated by a few percent compared to the model without post-perovskite given the same mass.

January 2008:

Lowell Observatory， Flagstaff, Arizona

Research with Mr. Brian W. Taylor from Boston University on adding time delay integration mode (TDI) on PRISM on Perkins Telescope.

★In January 2008, I went on MIT Astronomy Field Camp (a 9-unit IAP class) to Lowell Observatory. At Lowell, I did a 3-week project with Brian Taylor from Boston University on adding a new working mode, called Time Delay Integration Mode (also called strip scan mode which is different from the usual stare frame mode that most telescopes use), to PRISM (an optical camera system) on Perkins Telescope. Basically we calculated and programmed strip scan mode (viz. TDI mode) on CCD. The detail of this project is explained in the following powerpoint file:

Adding TDI mode to PRISM (Only for education purpose, if using it please cite it properly)

Please see Arizona Trip for some photos taken during this trip to Arizona.

Summer 2007:

MIT Department of Earth, Atmospheric and Planetary Science

Summer UROP with Prof. Sara Seager on Mass-Radius relation of Earth-like exoplanet.

★We Built Computer Models for the interior structure and the atmosphere of extra-solar planets to understand the Mass-Radius relation and atmospheric spectral lines of exoplanets. Our basic assumption for the interior of Earth-like exoplanets is that they all have an iron core, a silicate mantle and a water crust. We also assumed that the temperature dependence of the Equation Of State (EOS) is negligible, which is a very good approximation.

Based on these assumptions, we developed two computer codes in matlab to interpret the bulk composition of solid exoplanets based on their mass and radius measurements. These two codes are available on the website for download. If you have any questions regarding the code, please contact me or Prof. Sara Seager.

Exoplanet Code Download

Paper published on Publications of the Astronomical Society of the Pacific (PASP):

Li Zeng, and Sara Seager. A Computational Tool to Interpret the Bulk Composition of Solid Exoplanets based on Mass and Radius Measurements. In the Publications of the Astronomical Society of the Pacific (PASP), Chicago Journals, August 2008.

Home