The processes of star formation and planet formation are intricately linked through protostellar and protoplanetary disks. Material from the molecular cloud flows on to disks, where an array of physical processes compete to determine how quickly material drains from the disk on to the central star. The imbalance between these accretion rates sets the initial conditions for planet formation; it drives the observational signatures that we can observe with high resolution across the electromagnetic spectrum. It can even control the multiplicity of stellar systems. In this talk I will revisit two classic problems in astrophysics related to disk dynamics and planet formation: Bondi accretion and gravitational instability. For the former problem, I will describe a new model for Bondi accretion including the effects of radiative feedback, showing how radiative heating suppresses the growth rates of young giant planets. In the second part of the talk I will review the role of gravitational instability in protostellar disks, showing how we can better understand the growth of substructure using updated linear models inspired by the classic galactic spiral density wave theories of decades past.

Speaker: Kaitlin Kratter (The University of Arizona)

The 2026 Spring Colloquium talks are held on Wednesdays at 3:00 PM. This colloquium is hosted by STScI and will be held as an in-person and virtual event.

You may join in person at STScI’s John N. Bahcall Auditorium or virtually on the STScI Research YouTube channel.

Please direct questions or comments to contact above. The 2026 Spring Colloquium members are: Nimisha Kumari (STScI), Elena Manjavacas (STScI), Jack Neustadt (JHU), Kevin Schlaufman (JHU), Adam Smercina (STScI), Ethan Vishniac (JHU).