Nucleosynthesis in AGB stars traced by oxygen isotopic ratios I. Determining the stellar initial mass by means of the 17O/18O ratio ⋆

1R. de Nutte et al. (>10)
Astronomy & Astrophysics 600, A71 Link to Article [https://doi.org/10.1051/0004-6361/201629195]
1Institute of Astronomy, KU Leuven, Celestijnenlaan 200D B2401, 3001 Leuven, Belgium
e-mail: rutger.denutte@ster.kuleuven.be

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Calibration-free quantitative elemental analysis of meteor plasma using reference laser-induced breakdown spectroscopy of meteorite samples

1Martin Ferus et al. (>10)
Astronomy & Astrophysics 610, A73 Link to Article [https://doi.org/10.1051/0004-6361/201629950]
1J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, 18223 Prague 8, Czech Republic

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The Severny Kolchim Meteorite: New Data on Mineralogy

1Erokhin, Y.V., 1Koroteev, V.A., 1Khiller, V.V., 1Ivanov, K.S., 2Kleimenov, D.A.
Doklady Earth Sciences 482, 1189-1192 Link to Article [DOI: 10.1134/S1028334X18090118]
1Zavaritsky Institute of Geology and Geochemistry, Ural Branch, Russian Academy of Sciences, Yekaterinburg, 620016, Russian Federation
2Ural State Mining University, Yekaterinburg, 620144, Russian Federation

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Study of metallic Fe-Ni-Co alloy and stony part isolated from Seymchan meteorite using X-ray diffraction, magnetization measurement and Mössbauer spectroscopy

1Oshtrakh, M.I., 1Maksimova, A.A., 1Goryunov, M.V., 1,2Petrova, E.V., 3Felner, I., 1,4Chukin, A.V., 2Grokhovsky, V.I.
Journal of Molecular Structure 1174, 112-121 Link to Article [DOI: 10.1016/j.molstruc.2018.06.039]
1Department of Experimental Physics, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002, Russian Federation
2Department of Physical Techniques and Devices for Quality Control, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002, Russian Federation
3Racah Institute of Physics, The Hebrew University, Jerusalem, 91904, Israel
4Department of Theoretical Physics and Applied Mathematics, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002, Russian Federation

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Investigating the history of volatiles in the solar system using synchrotron infrared micro-spectroscopy

1King, A.J., 1Schofield, P.F., 2Stephen, N.R., 3Frogley, M.D., 3Cinque, G., 1Russell, S.S.
Infrared Physics and Technology 94, 244-249 Link to Article [DOI: 10.1016/j.infrared.2018.09.020]
1Planetary Materials Group, Department of Earth Sciences, Natural History Museum, London, SW7 5BD, United Kingdom
2Plymouth Electron Microscopy Centre & School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, United Kingdom
3Diamond Light Source Ltd, Harwell Science Campus, Didcot, OX11 0DQ, United Kingdom

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Oxygen Isotopic Exchange between Amorphous Silicate and Water Vapor and Its Implications for Oxygen Isotopic Evolution in the Early Solar System

1Daiki Yamamoto, 1Minami Kuroda,1,2Shogo Tachibana, 3Naoya Sakamoto, 1,4Hisayoshi Yurimoto
The Astrophysical Journal865, 98 Link to Article [https://doi.org/10.3847/1538-4357/aadcee]
1Department of Natural History Sciences, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
2UTokyo Organization for Planetary Space Science, The University of Tokyo, Hongo, Tokyo 113-0033, Japan
3Isotopic Imaging Laboratory, Hokkaido University, Sapporo, 001-0021, Japan
4Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa, 252-210, Japan

Meteoritic evidence suggests that oxygen isotopic exchange between 16O-rich amorphous silicate dust and 16O-poor water vapor occurred in the early solar system. In this study, we experimentally investigated the kinetics of oxygen isotopic exchange between submicron-sized amorphous forsterite grains and water vapor at protoplanetary disk-like low pressures of water vapor. The isotopic exchange reaction rate is controlled either by diffusive isotopic exchange in the amorphous structure or by the supply of water molecules from the vapor phase. The diffusive oxygen isotopic exchange occurred with a rate constant D (m2 s−1) = (1.5 ± 1.0) × 10−19 exp[−(161.5 ± 14.1 (kJ mol−1))R −1(1/T−1/1200)] at temperatures below ~800–900 K, and the supply of water molecules from the vapor phase could determine the rate of oxygen isotopic exchange at higher temperatures in the protosolar disk. On the other hand, the oxygen isotopic exchange rate dramatically decreases if the crystallization of amorphous forsterite precedes the oxygen isotopic exchange reaction with amorphous forsterite. According to the kinetics for oxygen isotopic exchange in protoplanetary disks, original isotopic compositions of amorphous forsterite dust could be preserved only if the dust was kept at temperatures below 500–600 K in the early solar system. The 16O-poor signatures for the most pristine silicate dust observed in cometary materials implies that the cometary silicate dust experienced oxygen isotopic exchange with 16O-poor water vapor through thermal annealing at temperatures higher than 500–600 K prior to their accretion into comets in the solar system.