相关论文: Generating potassium abundance variations in the S…
The elements in the universe are synthesized primarily in stars and supernovae, where nuclear fusion favors the production of even-Z elements. In contrast, odd-Z elements are less abundant and their yields are highly dependent on detailed…
Volatility-dependent fractionation of the rock-forming elements at high temperatures is an early, widespread process during formation of the earliest solids in protoplanetary disks. Equilibrium condensation calculations allow prediction of…
Condensation processes, which are responsible for the main chemical differences between gas and solids in the Galaxy, are the major mechanisms that control the cycle of dust from evolved stars to planetary systems. However, they are still…
Isotope anomalies provide important information about early solar system evolution. Here we report molybdenum isotope abundances determined in samples of various meteorite classes. There is no fractionation of molybdenum isotopes in our…
Lightning in the solar nebula is considered to be one of the probable sources for producing the chondrules that are found in meteorites. Gamma-ray bursts (GRBs) provide a large flux of gamma-rays that Compton scatter and create a charge…
We used chemical equilibrium calculations to model thermal metamorphism of ordinary chondritic material as a function of temperature, pressure, and trace element abundance and use our results to discuss volatile mobilization during thermal…
All cometary nuclei that formed in the early Solar System incorporated radionuclides and therefore were subject to internal radiogenic heating. Previous work predicts that if comets have a pebble-pile structure internal temperature build-up…
Dust grains of crystalline silicate, which are rarely presented in interstellar space, were found in cometary nuclei. These crystalline silicates are thought to have formed by annealing of amorphous silicate grains or direct condensation of…
We present three-dimensional numerical simulations of particle clumping and planetesimal formation in protoplanetary disks with varying amounts of solid material. As centimeter-size pebbles settle to the mid-plane, turbulence develops…
Planet formation occurs within the gas and dust rich environments of protoplanetary disks. Observations of these objects show that the growth of primordial sub micron sized particles into larger aggregates occurs at the earliest stages of…
Extensive photometric stellar surveys show that many main sequence stars show emission at infrared and longer wavelengths that is in excess of the stellar photosphere; this emission is thought to arise from circumstellar dust. The presence…
The core accretion scenario of planet formation assumes that planetesimals and planetary embryos are formed during the primordial, gaseous phases of the protoplanetary disk. However, how the dust particles overcome the traditional growth…
Meteoritic studies of solar system objects show evidence of nucleosynthetic heterogeneities that are inherited from small presolar grains (< 10 $\mu$m) formed in stellar environments external to our own. The initial distribution and…
The deuterium abundances inferred from observations of the interstellar medium within 1-2 kpc of the Sun range over a factor of three and the corresponding oxygen abundances show an even larger dispersion. While the lower D (and O)…
The Al/Si and Mg/Si ratios in non-carbonaceous chondrites are lower than the solar (i.e., CI-chondritic) values, in sharp contrast to the non-CI carbonaceous meteorites and the Earth, which are enriched in refractory elements and have Mg/Si…
High-resolution ALMA observations have revealed asymmetric dust crescents in several protoplanetary disks, suggesting efficient dust trapping mechanisms potentially linked to gas vortices. While such features have been associated with…
If Jupiter and the Sun both formed directly from the same well-mixed proto-solar nebula, then their atmospheric compositions should be similar. However, direct sampling of Jupiter's troposphere indicates that it is enriched in elements such…
Astronomical observations and analysis of stardust isolated from meteorites have revealed a highly diverse interstellar and circumstellar grain inventory, including a wide range of amorphous materials and crystalline compounds (silicates…
Despite the fact that the terrestrial planets formed from the protoplanetary disk, their compositions show marked departures from that of solar nebula condensates. Metallic cores fix oxygen fugacities ($f$O$_2$s) of the planets to 5…
Dynamical models of planet formation coupled with cosmochemical data from martian meteorites show that Mars' isotopic composition is distinct from that of Earth. Reconciliation of formation models with meteorite data require that Mars grew…