Disc-bearing young stellar objects at high angular resolution

Séminaire IPAG de Claire Davies (University of Exeter), jeudi 28 novembre 2019 à 11h00, IPAG seminar room

Direct observations of the innermost au of protoplanetary discs allow us to probe the inner disc structure and its impact on the bulk disc structural evolution (one potential product of which is the formation of planetary systems). For the closest young stellar objects (YSOs), the inner disc regions subtend an angle on the order of 10s of milliarcseconds at most - a distance scale only accessible to optical long baseline interferometry.

In the first section of my talk, I will focus on results from our survey of YSOs with the Center for High Angular Resolution Astronomy (CHARA) Array. In particular, I will present published results for the intermediate mass YSOs HD 142666, V1295 Aql and MWC 275 and the low mass YSO SU Aur as well as preliminary results for RY Tau. The 330 m baselines of CHARA have enabled us to spatially resolve the inner dust rims of the discs of these objects, revealing e.g. a range of grain growth efficiencies, the presence of additional optically thick material interior to the dust sublimation rim and additional physical processes which contribute to the excess infra-red continuum emission.

The second section of my talk will shift focus to the relative alignment of stars and their discs and how the typical Kant-Laplace nebula hypothesis concept of a single star with a circum-equatorial disc is being brought into question by recent high angular resolution observations.

In particular, I will discuss my recent work looking at how photometric variability of YSOs with spatially-resolved discs can be used to assess whether the degree of alignment present in the solar system can be considered to be normal.