相关论文: Cloudlet capture by Transitional Disk and FU Orion…
Both observations of arc-like structures and luminosity bursts of stars > 1 Myr in age indicate that at least some stars undergo late infall events. We investigate scenarios of replenishing the mass reservoir around a star via capturing and…
The earliest phases of star formation are characterised by intense mass accretion from the circumstellar disk to the central star. One group of young stellar objects, the FU Orionis-type stars exhibit accretion rate peaks accompanied by…
The recent identification of one or two sub-parsec disks of young, massive stars orbiting the ~4e6 solar mass black hole Sgr A* has prompted an "in-situ" scenario for star formation in disks of gas formed from a cloud captured from the…
I review some recent work on low-mass star formation, with an emphasis on theory, basic principles, and unresolved questions. Star formation is both a gravitational fragmentation problem as well as an accretion problem. Molecular cloud…
FU Orionis-type objects (FUors) are low-mass pre-main sequence stars undergoing a temporary, but significant increase of mass accretion rate from the circumstellar disk onto the protostar. It is not yet clear what triggers the accretion…
FU Orionis-type stars are young stellar objects showing large outbursts due to highly enhanced accretion from the circumstellar disk onto the protostar. FUor-type outbursts happen in a wide variety of sources from the very embedded ones to…
Our current understanding of the physical processes of star formation is reviewed, with emphasis on processes occurring in molecular clouds like those observed nearby. The dense cores of these clouds are predicted to undergo gravitational…
Accretion-driven luminosity outbursts are a vivid manifestation of variable mass accretion onto protostars. They are known as the so-called FU Orionis phenomenon in the context of low-mass protostars. More recently, this process has been…
Young stars and planetary systems form in molecular clouds. For classical T Tauri stars (CTTS, F-K type precursors) the accretion disk does not reach down to the central star, but it is truncated near the co-rotation radius. The inner edge…
We propose that the cloud moving on a highly eccentric orbit near the central black hole in our Galaxy, reported by Gillessen et al., is formed by a photoevaporation wind originating in a disk around a star that is tidally perturbed and…
This paper describes eruptive phenomena in pre-main sequence stars. The eruptions of FU Orionis stars have much in common with outbursts in other accreting systems, such as dwarf novae and some symbiotic stars. These common features are…
The origin of disks surrounding young stars has direct implications for our understanding of the formation of planetary systems. In the interstellar clouds from which star form, angular momentum is regulated by magnetic fields, preventing…
Recent observations have suggested that circumstellar disks may commonly form around young stellar objects. Although the formation of circumstellar disks can be a natural result of the conservation of angular momentum in the parent cloud,…
We present a new perspective on the crystallinity of dust in protoplanetary disks. The dominant crystallization by thermal annealing happens in the very early phases of disk formation and evolution. Both the disk properties and the level of…
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 stars $\leq~2$ Myr old harbour protoplanetary discs,…
Recent progress in the understanding of star formation is summarized. A consistent picture is emerging where molecular clouds form with turbulent velocity fields and clumpy substructure, imprinted already during their formation. The clouds…
Young stars orbiting in the gravitational potential well of forming star clusters pass through the cluster's dense molecular gas and can experience Bondi-Hoyle accretion from reservoirs outside their individual protostellar cloud cores.…
The capture of the free-floating planets and primordial black holes into a collapsing protostellar cloud is considered. Although the last stage of rapid contraction leading to the star formation lasts for a relatively short time $\sim 10^5$…
Young stellar systems orbiting in the potential of their birth cluster can accrete from the dense molecular interstellar medium during the period between the star's birth and the dispersal of the cluster's gas. Over this time, which may…
We study numerically the evolution of rotating cloud cores, from the collapse of a magnetically supercritical core to the formation of a protostar and the development of a protostellar disk during the main accretion phase. We find that the…