How do planets form?

We are living at a time in human history when we know that our galaxy is teeming with rocky planets like our own. Whether or not such planets are habitable is linked to the building blocks and raw materials that were present in their planetary nurseries. As it was forming 4.5 billion years ago, our own solar system was embedded within such a nursery, or protoplanetary disk, with the right conditions to form a habitable rocky planet with a gaseous atmosphere. Since we cannot go back in time to study these conditions in our own solar system, I turn to protoplanetary disks in our galaxy in order to understand how planets form.

Here are some articles and interviews about my work:
What Can a Young Star Teach Us about the Birth of Our Planet, Sun, and Solar System?
Finding Planets Before They Happen
Watching a Planet Being Born

Here is my plenary talk from the 223rd American Astronomical Society meeting (members only):
From Disks to Planets: Observing Planet Formation in Disks Around Young Stars


Credit: NAOJ

What are the footprints of forming planets?

As planets form, they create telltale footprints in the shape of ring-like gaps in the protoplanetary disk. This is because planets will accumulate and clear out the material around themselves as they form.  In order to catch planet formation in action, I search for gaps in protoplanetary disks.  I work with models and multiwavelength data to detect and measure the sizes of gaps in protoplanetary disks in order to link these measured observational properties to theoretical models.


Credit: NASA/JPL-Caltech/T. Pyle (SSC)

What is the timescale for planet formation?

Since significant gas must be present in the protoplanetary disk for gas giant planets to form, the lifetime of the protoplanetary disk places an upper limit on the timescale for giant planet formation. The longevity of gas in the disk is dictated by the rate at which gas is eroded by photoevaporative winds created by high-energy ionizing radiation from the central star.  I work to improve our understanding of disk photoevaporation by measuring infrared emission lines that have been proposed to be diagnostic of this high-energy radiation.


Credit: NASA/JPL-Caltech/R. Hurt (IPAC)

How do young protoplanetary systems change over time?

Studying the interaction between the protoplanetary disk and its host star is crucial since the star is the dominant heating source of the disk and, therefore, impacts the disk structure and composition. While we know that high-energy radiation fields of young stars are highly variable, we do not understand how or if the variability results in disk structural and compositional changes.  I work with multiwavelength, multiepoch data to trace the connection between changes in the high-energy emission of young stars and the surrounding disk.