Our Sun and planetary system were born about 4.5 billion years ago. How did this happen,
and what is the nature of our heritage from these early times? This review tries to address …

To understand how planetary systems form in the dusty disks around pre-main-sequence
stars, a detailed knowledge of the structure and evolution of these disks is required …

Abstract Michigan InfraRed Combiner-eXeter (MIRC-X) is a new highly sensitive six-
telescope interferometric imager installed at the CHARA Array that provides an angular …

Photonic technologies offer numerous functionalities that can be used to realize
astrophotonic instruments. The most spectacular example to date is the ESO Gravity …

Context. Optical long-baseline interferometry is moving a crucial step forward with the
advent of general-user scientific instruments that equip large aperture and hectometric …

An observational review is provided of the properties of accretion disks around young stars.
It concerns the primordial disks of intermediate-and high-mass young stellar objects in …

Context. It is now generally accepted that the near-infrared excess of Herbig AeBe stars
originates in the dust of a circumstellar disk. Aims. The aims of this article are to infer the …

Context. The innermost astronomical unit (au) in protoplanetary disks is a key region for
stellar and planet formation, as exoplanet searches have shown a large occurrence of close …

Variability in emission lines is a characteristic feature in young stars and can be used as a
tool to study the physics of the accretion process. Here, we present a study of Hα variability …

Context. Accretion and outflow processes are of fundamental importance for our
understanding of the formation of stars and planetary systems. To trace these processes …