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2023-03-14 Zhen Guo (NPF/Universidad de Valparaiso)

Episodic accretion on young stellar objects – results from the VVV survey

Abstract: The Pre-Main-Sequence stellar evolution is shaped by the mass accretion process. The variable nature of the mass accretion process on embedded young star objects (YSOs) has been discovered in recent years. High-amplitude irregular accretion bursts were observed across all wavelengths on timescales from months to decades, which are triggered by various instabilities throughout the accretion disc. On the other hand, periodic accretion bursts were detected among a group of embedded YSOs, which might be consequences of dynamical perturbations in young binary or star-planet systems. In the first part of the talk, I will present our latest search results on long-term eruptive YSOs from the decade-long near-IR VVV survey, including 15 new spectroscopically confirmed FUor-type objects. In the second part, I will briefly present my latest work on searching and monitoring periodic outbursting YSO candidates, that provide indirect evidence of early planet/companion formation.