The Accretion Processes in the Formation of Giant Exoplanets

Accretion rate is a critical parameter for studying planet formation. Discoveries of planets that are still in formation processes allow us to constrain the accretion rate with observations.

I worked with Prof. Gregory Herczeg to measure accretion rates of a few planetary-mass companions. In this project, we used the Hubble Space Telescope (HST) photometry to determine the accretion-induced excess emissions in H-alpha and UV Balmer continuum. We then converted these emissions into accretion luminosity and mass accretion rates. Our study also suggested the strong H-alpha emission from the companions can reduce the brightness contrast and increase the success rate for discovering new directly-imaged exoplanets.

Currently, I am leading a team to observe the PDS70 system in H-alpha and UV. We are conducting angular differential imaging observations with HST and aim to obtain the images of PDS70b(c) in the F656N and F336W bands. If successful, this experiment will provide the first-ever exoplanet image in the UV band. Then these observations will allow us to accurately determine the mass accretion rate onto PDS70b(c).