The Demographics of Pre-main Sequence Stars and their Disks

Planets form in “protoplanetary disks,” rotating disks of gas and dust that form around young stars. The properties of planets in our own Solar System, as well as those of the many exoplanets that are now being discovered, can be tied back to the conditions in these disks. Even so, the most commonly studied protoplanetary disks have already had a few million years to process material, and they already show signs that planet formation may be well underway. Some even show evidence that they may be harboring planets that have already formed, so their properties do not reflect the starting point of planet formation, yielding less stringent constraints on theories of planet formation. To better understand how planet formation begins in protoplanetary disks, this project will determine the properties of infant protoplanetary disks that are less than one million years old and thus better represent the earliest stages of planet formation. Understanding their properties will therefore place important constraints on the physics of how planets form, shedding light on how the Solar System came to be, and its place in the growing population of exoplanetary systems. This project will train a graduate student in astrophysics and expose high school students to astronomy research. To measure the properties of the youngest protoplanetary disks, the research team will use cutting edge AI/machine learning techniques to develop efficient tools for carrying out forward modeling of protoplanetary disk radiative transfer models to ALMA and VLA observations. They will then apply this advanced framework to ALMA/VLA observations of the entire population of young (<1 Myr-old) protostellar disks in Taurus to determine their structure and to assess how capable they are of forming planets. This work will produce the first comprehensive picture of young protostellar disk demographics, including gas and dust masses and sizes that inform the masses of and locations where planets can be formed, dust grain sizes which provide a measure of the state of ongoing planet formation, and protostellar masses that are important for putting these results within the context of their host (proto-)star. Together, these projects will lay the groundwork for significant improvements to our understanding of the planet formation process. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.