相关论文: Disks, young stars, and radio waves: the quest for…
The destiny of planetary systems through the late evolution of their host stars is very uncertain. We report a metal-rich gas disk around a moderately hot and young white dwarf. A dynamical model of the double-peaked emission lines…
The high rate of planet detection among solar-type stars argues that planet formation is common. It is also generally assumed that planets form in protoplanetary discs like those observed in nearby star forming regions. On what timescale…
Nearly all young stars are initially surrounded by `protoplanetary' discs of gas and dust, and in the case of single stars at least 30\% of these discs go on to form planets. The process of protoplanetary disc formation can result in…
Since the first massive planet in a short period orbit was discovered, the question arised how such an object could have formed. There are basically two formation scenarios: migration due to planet-disk or planet-planet interaction. Which…
The dominant accretion process leading to the formation of the terrestrial planets of the Solar System is a subject of intense scientific debate. Two radically different scenarios have been proposed. The classic scenario starts from a disk…
Meteorites, which are remnants of solar system formation, provide a direct glimpse into the dynamics and evolution of a young stellar object (YSO), namely our Sun. Much of our knowledge about the astrophysical context of the birth of the…
Among the numerous known extrasolar planets, only a handful have been imaged directly so far, at large orbital radii and in rather evolved systems. The Atacama Large Millimeter/submillimeter Array (ALMA) will have the capacity to observe…
Understanding the physics of how stars form is a highly-prioritized goal of modern Astrophysics, in part because star formation is linked to both galactic dynamics on large scales and to the formation of planets on small scales. It is…
We examine the formation of planets around binary stars in light of the recently discovered systems Kepler 16, 34 and 35. We conduct hydrodynamical simulations of self gravitating disks around binary systems. The selected binary and disk…
Recent ALMA observations indicate that the majority of bright protoplanetary discs show signatures of young moderately massive planets. I show that this result is paradoxical. The planets should evolve away from their observed states by…
Terrestrial planets and the cores of giant planets are thought to be built by the collisional agglomeration of solids spanning over 20 orders of magnitude in size within a few million years. However, there is tension between this basic…
While it may seem counterintuitive that X-ray astronomy should give any insights into low-temperature planetary systems, planets orbit stars whose magnetized surfaces divert a small fraction of the stellar energy into high energy products:…
This chapter explores the physics shared by planetary rings and the various disks that populate the Universe. It begins with an observational overview, ranging from protoplanetary disks to spiral galaxies, and then compares and contrasts…
Advances in the discovery and characterization of asteroids over the past decade have revealed an unanticipated underlying structure that points to a dramatic early history of the inner Solar System. The asteroids in the main asteroid belt…
Observational studies showed that galaxy disks are already in place in the first few billion years of the universe. The early disks detected so far, with typical half-light radii of 3 kiloparsecs at stellar masses around 10^11 M_sun for…
The evolution of circumstellar discs is influenced by their surroundings. The relevant processes include external photoevaporation due to nearby stars, and dynamical truncations. The impact of these processes on disc populations depends on…
The first long-baseline ALMA campaign resolved the disk around the young star HL Tau into a number of axisymmetric bright and dark rings. Despite the very young age of HL Tau these structures have been interpreted as signatures for the…
Debris disks are the dust disks found around ~20% of nearby main sequence stars in far-IR surveys. They can be considered as descendants of protoplanetary disks or components of planetary systems, providing valuable information on…
Star formation involves the flow of gas and dust within molecular clouds into protostars and young stellar objects (YSOs) due to gravity. Along the way, these flows are shaped significantly by many other mechanisms, including pressure,…
Meteorites, and in particular primitive meteorites (chondrites), are irreplaceable probes of the solar protoplanetary disk. We review their essential properties and endeavour to place them in astrophysical context. The earliest solar system…