Daftar Isi: Observations of star-disk interaction and link to disk evolution at the epoch of planet formation

Daftar Isi:

Our view of the star-disk interaction has recently been revolutionized by space-borne missions like CoRoT and Kepler/K2. Thanks to their sub-1% photometric precision, sub-hour sampling, and continuous monitoring for weeks to months, these campaigns have provided first detailed atlases of the short- to mid-term variability of young stars, thus revealing the manifold photometric behaviors of disk-bearing objects. In this review, we explore the observational signatures and intrinsic timescales of the various physical processes at play in young star-disk systems. At least two distinct paradigms of star-disk interaction emerge: i) the unstable regime, characterized by stochastic, short-lived accretion bursts and rapidly evolving accretion features; ii) the stable regime, with ordered accretion streams from the inner disk to the star, and accretion features that persist over many rotational cycles. These distinct scenarios may be related to different stages of the inner disk evolution. The mechanisms which regulate the star-disk interaction on timescales of days typically exhibit a relatively stable nature on timescales of years, although with a more erratic behavior on the shorter term.