Related papers: Brown dwarf formation by binary disruption
Brown dwarfs and very low mass stars are a significant fraction of stars in our galaxy, and they are interesting laboratories to investigate planet formation in extreme conditions of low temperature and densities. In addition, the dust…
Most of massive stars form in binary or higher-order systems in clumpy, sub-structured clusters. In the very first phases of their life, these stars are expected to interact with the surrounding environment, before being released to the…
Understanding the formation of wide binary systems of very low mass stars (M $\le$ 0.1 Msun) is challenging. The most obvious route is via widely separated low-mass collapsing fragments produced through turbulent fragmentation of a…
One of the characteristic features of low-mass stars is their propensity to shed large amounts of angular momentum throughout their evolution. This distinguishs them from brown dwarfs which remain fast rotators over timescales of gigayears.…
We present radiation hydrodynamic simulations in which binary planets form by close encounters in a system of several super-Earth embryos. The embryos are embedded in a protoplanetary disk consisting of gas and pebbles and evolve in a…
In dense stellar systems the frequent dynamical interactions between stars play a crucial role in the formation and evolution of compact binaries. We study these processes using a novel approach combining a state-of-the-art binary…
We present results from high-resolution hydrodynamical simulations which explore the effects of small scale clustering in star-forming regions. A large ensemble of small-N clusters with 5 stellar seeds have been modelled and the resulting…
Hot subdwarfs are core-helium burning stars that show lower masses and higher temperatures than canonical horizontal branch stars. They are believed to be formed when a red giant suffers an extreme mass-loss episode. Binary interaction is…
We present a high-contrast imaging survey of intermediate-mass (1.75--4.5 $M_\odot$) stars to search for the most extreme stellar binaries, i.e., for the lowest mass stellar companions. Using adaptive optics at the Lick and Gemini…
The initial distribution of rotational velocities of stars is still poorly known, and how the stellar spin evolves from birth to the various end points of stellar evolution is an actively debated topic. Binary interactions are often invoked…
While brown dwarfs show similarities with stars in their early life, their spin evolution is much more akin to that of planets. We have used lightcurves from the K2 mission to measure new rotation periods for 18 young brown dwarfs in the…
We argue that gravitational instability of typical protostellar disks is not a viable mechanism for the fragmentation into multiple systems -- binary stars, brown dwarf companions, or gas giant planets -- except at periods above roughly…
We examine the spatial distribution of brown dwarfs produced by the decay of small-N stellar systems as expected from the embryo ejection scenario. We model a cluster of several hundred stars grouped into 'cores' of a few stars/brown…
In this paper, the first of a series, we study the stellar dynamical and evolutionary processes leading to the formation of compact binaries containing white dwarfs in dense globular clusters. We examine the processes leading to the…
Spirals and streamers are the hallmarks of mass accretion during the early stages of star formation. We present the first observations of a large-scale spiral and a streamer towards a very young brown dwarf candidate in its early formation…
We have carried out numerical evolutionary calculations of binary systems to investigate the formation of binary millisecond pulsars (pulsars with white dwarf companions). We apply the ``standard scenario'' in which the binary pulsars are…
Wide gravitationally bound pairs of stars can be formed from adjacent prestellar cores that happen to move slowly enough relative to each other. These binaries are remnants of the primordial clustering. It is shown that the expected…
I present observations of a new faint double, 2MASS J11011926-7732383AB, toward the Chamaeleon I star-forming region. From optical and near-infrared images of the pair, I measure a separation of 1.44" and extract RIJHK_s photometry of the…
We report the statistical properties of stars, brown dwarfs and multiple systems obtained from the largest radiation hydrodynamical simulation of star cluster formation to date that resolves masses down to the opacity limit for…
The large scale structure of a brown dwarf atmosphere is determined by an interplay of convection, radiation, dust formation, and gravitational settling, which possibly provides an explanation for the observed variability. The result is an…