NTNU ES-CAG joint colloquium

How stellar multiplicity shapes disc evolution and planet formation / Dr Jeremy Smallwood (University of Oklahoma)

Abstract: Spectacular high-resolution imagery from the last decade has revealed that planet formation begins during the turbulent early stages of star formation, when stellar interactions profoundly shape protoplanetary disc structure. Observational evidence increasingly suggests that even apparently isolated stars bear the signatures of past stellar flybys -- encounters that leave lasting imprints on disc morphology and may trigger the onset of planet formation. With the majority of stars residing in binary or higher-order multiple systems, these interactions become even more significant. In such environments, circumbinary discs can become misaligned with the binary orbital plane, creating distinctive conditions for circumbinary (P-type) planet formation. Binary companions also truncate their circumstellar discs, directly affecting the formation efficiency of circumstellar (S-type) planets. Recent observations of circumtriple disc architecture further raise intriguing questions about the viability of circumtriple planet formation. I will demonstrate that stellar multiplicity is not merely incidental but fundamental to understanding disc evolution and the diverse pathways of planet formation throughout the galaxy.