We have performed smoothed particle radiation magnetohydrodynamics (SPRMHD) simulations of the collapse of rotating, magnetised molecular cloud cores to form protostars. The calculations follow the formation and evolution of the first hydrostatic core, the collapse to form a stellar core, the launching of outflows from both the first hydrostatic core and stellar cores, and the breakout of the s...

Stellar interiors are the seat of efficient transport angular momentum all along their evolution. Understanding dependence turbulent triggered by shear instabilities due to differential rotation in stellar radiation zones is mandatory. Indeed, it constitutes one cornerstones rotational and mixing theory which implemented evolution codes predict chemical evolutions stars. We investigate horizont...

Observations of stars in the vicinity of the Sun show that binary systems are prevalent and appear to be a general outcome of the star-formation process. One of the major goals of this research is to understand the nature of the formation of binary and multiple stellar systems with typical low-mass stars (∼ 0.2 to 3 M ) and the physical properties of these systems. Basic questions concerning th...

Dust grains, formed around asymptotic giant branch (AGB) stars, are accelerated by stellar radiation to drive stellar winds, which supply freshly synthesized nuclides to the Galaxy. Silicate is the dominant dust species in space, but ~40% of oxygen-rich AGB stars are thought to have comparable amounts of aluminum oxide dust. Dust formation and the wind-driving mechanism around these oxygen-rich...

We present a model for the formation of high-mass close binary systems in the context of forming massive stars through gas accretion in the centres of stellar clusters. A low-mass wide binary evolves under mass accretion towards a high-mass close binary, attaining system masses of order 30-50 M⊙at separations of order 1 AU. The resulting high frequency of binary systems with two massive compone...

Accretion onto compact stellar objects (white dwarfs, neutron stars, and black holes) from companions in close binaries is the primary beacon for study of the astrophysics of the extreme: from endpoints of stellar and binary evolution, to the physical processes in the extremes of gravity, radiation, or magnetic fi elds. Accretion from the interstellar medium on the presumed still larger populat...

We consider the effects of an outflow on radiation escaping from the infalling envelope around a massive protostar. Using numerical radiative transfer calculations, we show that outflows with properties comparable to those observed around massive stars lead to significant anisotropy in the stellar radiation field, which greatly reduces the radiation pressure experienced by gas in the infalling ...