相关论文: The Pre--Main-Sequence of A-type stars
The formation of supermassive stars is believed to be an essential intermediate step for the formation of the massive black hole seeds that become the supermassive black holes powering the quasars observed in the early Universe. Numerical…
Periodic increases in luminosity arising from variable accretion rates have been predicted for some close pre-main sequence binary stars as they grow from circumbinary disks. The phenomenon is known as "pulsed accretion" and can affect the…
Due to their wide wavelength coverage across the millimetre to centimetre (mm - cm) range and their increased sensitivity, modern interferometric arrays facilitate observations of the thermal and non-thermal emission from different stellar…
Background: low-mass stars are the dominant product of the star formation process, and they trace star formation over the full range of environments, from isolated globules to clusters in the central molecular zone. In the past two decades,…
Massive, early-type stars deposit energy and momentum in the interstellar medium through dense, supersonic winds. These objects are one of the most important sources of ionising radiation and chemical enrichment in the Galaxy. The physical…
Parameter regions in which stars can become pulsationally unstable are found throughout the Hertzsprung-Russel diagram. Stars of high, intermediate, low and very low masses may cross various instability regions along their paths of…
The development of perturbations in the circumstellar disks of pre-main-sequence stars caused by clumpy accretion was investigated. Here we perform 3D hydrodynamical smoothed particle hydrodynamics simulations of disks perturbed by a recent…
A model of core-clump accretion with equally likely stopping describes star formation in the dense parts of clusters, where models of isolated collapsing cores may not apply. Each core accretes at a constant rate onto its protostar, while…
We study the accretion properties of pre-main sequence low-mass stars in the LH 91 association within the Large Magellanic Clouds. Using optical multiband photometry obtained with the Hubble Space Telescope, we identify 75 candidates…
Young solar-type stars grow through the accretion of material from the circumstellar disk during pre-main sequence (PMS) evolution. The ultraviolet radiation generated in this process plays a key role in the chemistry and evolution of young…
Accreting main-sequence stars expand significantly when the mass accretion timescale is much shorter than their thermal timescales. This occurs during mass transfer from an evolved giant star onto a main-sequence companion in a binary…
In the earliest phases of their evolution, stars gain mass through the acquisition of matter from their birth clouds. The widely accepted classical concept of early stellar evolution neglects the details of this accretion phase and assumes…
Recent numerical simulations have shown that the unstable disk within the central regime of the primordial gas cloud fragments to form multiple protostars on several scales. Their evolution depends on the mass accretion phenomenon,…
Young stars are expected to gain most of their mass by accretion from a disk that forms around them as a result of angular momentum conservation in the collapsing protostellar cloud. Accretion initially proceeds at high rates of…
The inner regions of protoplanetary disks are the locations where most of planets are thought to form and where processes that influence the global evolution of the disk, such as MHD-winds and photoevaporation, originate. Transition disks…
Protoplanetary disks are often assumed to change slowly and smoothly during planet formation. Here, we investigate the time evolution of isolated disks subject to viscosity and a disk wind. The viscosity is assumed to increase rapidly at…
A comparison of the hot and cool boundaries of the classical instability strip with observations has been an important test for stellar structure and evolution models of post- and main sequence stars. Over the last few years, the number of…
Molecular outflows in the form of wide-angle winds and/or well-collimated jets are associated with young stellar objects of all luminosities. Independent studies have established that the mass outflow rate is proportional to L_bol^0.6 for…
We report the results of a study of the intermediate and high mass stars in the young, rich star-forming complex IC 1805, based on a combination of optical, near-infrared, and mid-infrared photometry, and classification spectra. These data…
The first phase of stellar evolution in the history of the Universe may be Dark Stars, powered by dark matter heating rather than by nuclear fusion. Weakly Interacting Massive Particles, which may be their own antipartners, collect inside…