Date: 15.04.2025

Michał Siwak (UKEN,PL)

Accretion variability in Young Stars from the observer perspective -- from ordinary T~Tauri-type phase to FU~Ori-type enhanced accretion

Abstract:
I will discuss a few results obtained for Young Stellar Objects (YSOs), still accreting mass from their discs. On the example of T Tauri, I will show methodology commonly applied by researchers to characterise "slowly accreting" ordinary Class I and II YSOs. From time to time, due to e.g. gravitational instability, or close passage of nearby component, stars like T Tauri do experience the phase of enhanced accretion. YSOs experiencing this phase are classified as FUors, EXors or intermediatte cases. I will show our efforts to discover more examples of eruptive YSOs to increase statistic of well-characterised cases for more general theoretical studies. I will also mention my method that, under favorable circumstances, may allow to recreate the image of the inner disc in FU Ori-type stars.