I am currently an Associate Adjunct Professor in the Astronomy Department at the University of California, Berkeley.

My expertise is in providing direct images of planetary systems around nearby stars. I use some of the world's most advanced observatories, such as the Hubble Space Telescope, Keck Observatory, and the Gemini Telescopes. One remarkable image is the planetary system surrounding Fomalhaut (see below), which is a bright star located 25 light years away in the constellation Pisces Australis. Though direct images are difficult to obtain and currently quite rare, they provide unique and fundamental information about exoplanetary systems, such as:

• The masses of exoplanets, by analyzing how bright they appear and how stable their orbits should be assuming different properties.
• Their composition, by analyzing the color of thermal emission from the planet, or by obtaining a spectrum.
• The origin of exoplanets, by comparing their current observed properties with simulations of how planets form in a circumstellar disk and subsequently evolve.

Ultimately, these data will give us an empirical notion of how common or rare our own planetary system must be in our own galaxy and throughout the universe.

The Exoplanet Fomalhaut b

For images concerning Fomalhaut b, the recent visible light detection of an exoplanet candidate orbiting the bright star Fomalhaut, please see the NASA and Space Telescope Science Institute press releases:

• 2005: Elusive Planet Reshapes a Ring Around Neighboring Star
• 2008: Hubble Directly Observes Planet Orbiting Fomalhaut
• 2013: Hubble Reveals Rogue Planetary Orbit for Fomalhaut b

For the publicly accessible manuscripts related to these discoveries from our group:

• 2005: A planetary system as the origin of structure in Fomalhaut's dust belt
• 2008: Optical Images of an Exosolar Planet 25 Light Years from Earth
• 2009: Fomalhaut's Debris Disk and Planet: Constraining the Mass of Fomalhaut b From Disk Morphology
• 2013: STIS Coronagraphic Imaging of Fomalhaut: Main Belt Structure and the orbit of Fomalhaut b (submitted for peer review, The Astrophysical Journal)

I have also posted some of my dynamical studies on YouTube (click on image).

The Gemini Planet Imager

We should be commissioning the Gemini Planet Imager in mid 2013. GPI is an advanced adaptive optics system and coronagraph designed to directly detect warm planets and debris belts surrounding young stars such as Fomalhaut. We expect that by 2014 various GPI science projects will discover and characterize 10x more exoplanets via direct imaging and spectroscopy than existed in 2011. Please see the GPI website for more info. This project has been ten years in the making, and I currently serve on the GPI Science Steering Committee and the Debris Disk Science Team.

Spirit of Lyot Conferences

In 2007 I founded the Spirit of Lyot conference. The fundamental motivation is to nurture a balance between scientific talent and experimental innovation that is personified by the career of the famous French astronomer Bernard Lyot, inventor of the solar coronagraph.

In 2010 our colleagues in France hosted the second Spirit of Lyot conference in Paris, with a 50 percent increase in attendance.

In 2013 we will announce the third Lyot conference, probably to take place in 2014.