The innermost astronomical unit of protoplanetary disks

TL;DR

This review discusses how optical interferometry enables the study of the innermost regions of protoplanetary disks around young stars, crucial for understanding planet formation and disk dynamics.

Contribution

It provides a comprehensive overview of interferometric studies of young stellar objects' inner disks and explores future research prospects.

Findings

Optical interferometry uniquely resolves the first few astronomical units of disks.

Studies reveal detailed disk structures and physical conditions in the innermost regions.

Future interferometric techniques will enhance understanding of planet formation environments.

Abstract

Circumstellar disks around young stars are the birthsites of planets. It is thus fundamental to study the disks in which they form, their structure and the physical conditions therein. The first astronomical unit is of great interest because this is where the terrestrial-planets form and the angular momentum is controled via massloss through winds/jets. With its milli-arcsecond resolution, optical interferometry is the only technic able to spatially resolve the first few astronomical units of the disk. In this review, we will present a broad overview of studies of young stellar objects with interferometry, and discuss prospects for the future.