RUI: assessing the role of episodic accretion in the formation of STARS

Middlebury College received a $272,913 Project Grant from the National Science Foundation (NSF) Division of Astronomical Sciences under the Mathematical and Physical Sciences program (CFDA 47.049), effective September 1, 2025 through August 31, 2029. The award supports theoretical research assessing episodic accretion in star formation, with the primary deliverable being scientific investigation into how stars accumulate mass through variable accretion processes. The investigator will couple magnetohydrodynamical simulations with radiative transfer models to generate synthetic protostar observations and compare results against published observational data, ultimately advancing understanding of the physics governing mass accretion onto young stars and the role of accretion variability in stellar formation.

Beyond core research deliverables, the award includes broader impacts components providing training and professional development opportunities for undergraduate students and expanding public astronomy outreach programming in rural Vermont. No subawards are planned for this project. The funding aligns with NSF's mission to strengthen the Nation's scientific enterprise through fundamental research that advances scientific knowledge while integrating educational and workforce development activities.

Abstract

A general framework describing how STARS form has existed for decades. However, the details of how mass flows from larger-scale structures onto STARS remains unclear. There is some evidence that the growth of STARS is episodic in nature. Despite there being some evidence to support this picture, the true growth history of STARS remains unknown. The investigator will perform theoretical work to reveal how STARS gain their mass. This research will also provide training and professional development opportunities to undergraduate students and support the expansion of public astronomy outreach offerings in rural vermont. Mass accretion onto at least some STARS exhibits strong temporal variability, with direct detection of occasional large-amplitude bursts. In the episodic accretion scenario, large accretion luminosity changes will modify the temperature of the surrounding material, moving the boundaries between gas and solid phases for various species and driving irreversible chemical changes that will persist into the planet formation epoch. The investigator will assess the viability of stochastic and secular accretion scenarios by coupling existing (magneto)hydrodynamical simulations with evolutionary radiative transfer models, generating synthetic observations of protostars, and performing an apples-to-apples comparison with published observations. This work will ultimately investigate the physics governing accretion onto young STARS and the role played by accretion variability in the formation of STARS. 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.- subawards are not planned for this award.