Accretion through circumstellar disks plays an important role in star formation and in
establishing the properties of the regions in which planets form and migrate. The …

Star and planet formation are the complex outcomes of gravitational collapse and angular
momentum transport mediated by protostellar and protoplanetary disks. In this review, we …

We review current understanding of star formation, outlining an overall theoretical framework
and the observations that motivate it. A conception of star formation has emerged in which …

Spin is a fundamental property of all elementary particles. Classically it can be viewed as a
tiny magnetic moment, but a measurement of an electron spin along the direction of an …

Protoplanetary disks are quasi-steady structures whose evolution and dispersal determine
the environment for planet formation. I review the theory of protoplanetary disk evolution and …

Flattened, rotating disks of cool dust and gas extending for tens to hundreds of astronomical
units are found around almost all low-mass stars shortly after their birth. These disks …

Episodic accretion has become a recent focus of attention in the star-and planet-formation
community, turning into a central topic to understand the evolution of protostars and …

We review the role of stellar flybys and encounters in shaping planet-forming discs around
young stars, based on the published literature on this topic in the last 30 years. Since most …

Recent discoveries of extrasolar planets and new direct evidence for protoplanetary disks
around young stars have had a major impact on our understanding of star and planet …

We present a grid of radiation transfer models of axisymmetric young stellar objects (YSOs),
covering a wide range of stellar masses (from 0.1 to 50 M☉) and evolutionary stages (from …