相关论文: Giant planet and brown dwarf formation
The statistical properties of planets in binaries were investigated. Any difference to planets orbiting single stars can shed light on the formation and evolution of planetary systems. As planets were found around components of binaries…
The relative abundance of deuterium and hydrogen is a potent tracer of planet formation and evolution. Jupiter and Saturn have protosolar atmospheric D/H ratios, a relic of substantial gas accretion from the nebula, while the atmospheres of…
Stars and planets are the fundamental objects of the Universe. Their formation processes, though related, may differ in important ways. Stars almost certainly form from gravitational collapse and probably have formed this way since the…
Recent spacecraft observations exploring solar system properties impact standard paradigms of the formation of stars, planets and comets. We stress the unexpected cloud of microscopic dust resulting from the DEEP IMPACT mission, and the…
The recent discoveries of massive planets on ultra-wide orbits of HR 8799 (Marois et al. 2008) and Fomalhaut (Kalas et al. 2008) present a new challenge for planet formation theorists. Our goal is to figure out which of three giant planet…
There has been a long-standing discussion in the literature as to whether core accretion or disk instability is the dominant mode of planet formation. Over the last decade, several lines of evidence have been presented showing that core…
Measuring the occurrence rates of celestial objects is a valuable way to study their origins and evolution. Giant planets and brown dwarfs produce large Doppler signatures that are easily detectable by modern instrumentation, and legacy…
We conjecture that brown dwarfs are substellar objects because they have been ejected from small newborn multiple systems which have decayed in dynamical interactions. In this view, brown dwarfs are stellar embryos for which the star…
The giant planets of the solar system likely played a large role in shaping the architecture of the terrestrial planets. Using an updated collision model, we conduct a suite of high resolution N-body integrations to probe the relationship…
Brown dwarfs, being transitional objects between giant planets and low-mass stars, possess dense, cool interiors that provide optimal conditions to explore non-standard physics. Capture and accumulation of dark-matter particles can alter…
Giant planets are tens to thousands of times as massive as the Earth, and many times as large. Most of their volumes are occupied by hydrogen and helium, the primary constituents of the protostellar disks from which they formed.…
Understanding how giant and terrestrial planets form and evolve, what is their internal structure and that of their atmosphere, represents one of the major challenges of modern astronomy, which is directly connected to the ultimate search…
Young brown dwarfs and directly-imaged exoplanets have enticingly similar photometric and spectroscopic characteristics, indicating that their cool, low gravity atmospheres should be studied in concert. Similarities between the peculiar…
The ubiquity of planets and diversity of planetary systems reveal planet formation encompass many complex and competing processes. In this series of papers, we develop and upgrade a population synthesis model as a tool to identify the…
The formation and evolution of brown dwarfs are currently "hot topics" in cool star research. Latest observations and modeling efforts on disks, accretion, outflows, spatial distribution, and binarity in the context of the formation by…
We show that the dearth of brown dwarfs in short-period orbits around Solar-mass stars - the brown dwarf desert - can be understood as a consequence of inward migration within an evolving protoplanetary disc. Brown dwarf secondaries forming…
We suggest that low-mass hydrogen-burning stars like the Sun should sometimes form with massive extended discs; and we show, by means of radiation hydrodynamic simulations, that the outer parts of such discs (R>100 AU) are likely to…
The existence of giant planets on wide orbits ($\stackrel{>}{_\sim}100$AU) challenge planet formation theories; the core accretion scenario has difficulty in forming them, whereas the disc instability model forms an overabundance of them…
Doppler surveys have shown that more massive stars have significantly higher frequencies of giant planets inside $\sim$ 3 AU than lower mass stars, consistent with giant planet formation by core accretion. Direct imaging searches have begun…
Astronomers have discovered thousands of planets outside the solar system, most of which orbit stars that will eventually evolve into red giants and then into white dwarfs. During the red giant phase, any close-orbiting planets will be…