Condensation and Accretion of Corundum and Corundum-hibonite Grains in the Solar Nebura
نویسندگان
چکیده
SOLAR NEBURA. T. M. Nakamura, N. Sugiura, M. Kimura, A. Miyazaki, and A. N. Krot, Department of Earth and Planetary Science, Graduated School of Science, University of Tokyo, Tokyo 113-0033, Japan. ([email protected]), Faculty of Science, Ibaraki University, Mito 310-8512, Japan. Hawai’i Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai’i at Manoa, Honolulu, HI 96822, USA.
منابع مشابه
Oxygen Isotopic Compositions of Solar, Micrometer-sized Corundum, Hibonite and Spinel Grains in Acid-resistant Residues from Ordinary and Carbonaceous
Introduction: Isotopic studies of the very refractory solar condensates can potentially provide important constraints on the initial O-isotope composition of the solar nebula and its evolution [1,2]. Based on the narrow range of O-isotope composition (Δ 17 O ~ −24±2‰, 2σ) of primary minerals in FUN and non-FUN CAIs, which avoided postcrystallization isotope exchange, from CR and CV chondrites, ...
متن کاملCircumstellar Hibonite and Corundum and Nucleosynthesis in Asymptotic Giant Branch Stars
We report the discovery of two hibonite grains (CaAl12O19) whose isotopic compositions show that they formed in the winds of red giant and asymptotic giant branch (AGB) stars. While hibonite is the second major phase (after corundum, Al2O3) expected to condense from stellar ejecta with , it has not previously been found. C/O ! 1 One circumstellar hibonite grain is highly enriched in O and sligh...
متن کاملRevised Thermodynamic Properties of Ca Aluminates: Implications for the Condensation
Introduction: The Ca-aluminates such as hibonite, CaAl 12 O 19 , grossite, CaAl 4 O 7 , and dmitryivanovite, CaAl 2 O 4 , belong to a suite of the most refractory minerals that could condense from a solar or fractionated nebular gas. While dmitryivanovite is a rather rear mineral found so far only in a few CAIs from the CH chondrites [1,2], both hibonite and grossite are fairly common [3] being...
متن کاملCondensation Anisotropy of Corundum around Agb Stars and Its Effect on Infrared Spectra
Introduction: Dust formation in mass-loss winds from asymptotic giant branch (AGB) stars is a key process for acceleration of outflows. Equilibrium condensation calculations [e.g., 1] predict that corundum (Al2O3) is one of the first condensates around oxygenrich AGB stars. The presence of presolar corundum grains originated from AGB stars in chondrites [e.g., 25] is also a strong evidence of c...
متن کاملMagnesium Isotopic Compositions of Cm Hibonite Grains
Introduction: Hibonite is thought to be one of the earliest solids in the solar system, occurring as either a condensate or refractory residue, therefore the Mg isotope compositions of hibonite grains can help elucidate the initial abundance and distribution of Al in the early solar system. Previous investigations [1-6] of CM hibonite grains have demonstrated that hibonite shows a bimodal patte...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2006