My research interests include the compositions of extrasolar rocky objects and the fate of planetary systems around white dwarfs.

White dwarfs are the final stage of stellar evolution and most stars will end up as a white dwarf. Recent studies show that at least some fraction of extrasolar asteroids and planets can survive to the staròÀÙs white dwarf phase. Occasionally, an asteroid can be perturbed into the white dwarfòÀÙs tidal radius and get disrupted. This process often creates a hot dust disk very close to the white dwarf. Measuring the atmospheric compositions of externally-polluted white dwarfs can provide unique information about the composition of those extraterrestrial material.

Sometimes, there is unexpected discovery... one of them is highlighted in this recent news article: Can Planets Be Rejuvenated Around Dead Stars?

Broadly speaking, I work on...

1. 1.Measure the compositions of extrasolar rocky material
   

2. 2.Characterize the circumstellar environment around white dwarfs
   

3. 3.Other projects
   

ˆàˆàˆà - Where is the planet?

ˆàˆàˆà - Circumstellar gas from a disintegrating extrasolar asteroid?

Because a white dwarfòÀÙs atmosphere is very clean (pure H or He), even a small amount of heavy elements will be easily detectable. I have been using high-resolution spectrographs on Keck, the Very Large Telescope, Magellan and the Hubble Space Telescope to observe these heavily polluted white dwarfs and understand the composition of its accreting material.

Welcomeˆàˆàˆà Researchˆàˆàˆà CVˆàˆàˆà Othersˆàˆàˆà MJ