The Monitor project: rotation of low-mass stars in the open cluster M34     

Jonathan Irwin  Suzanne Aigrain  Simon Hodgkin  Mike Irwin  Jerome Bouvier  Cathie Clarke  Leslie Hebb  Estelle Moraux 《Monthly notices of the Royal Astronomical Society》2006,370(2):954-974

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Pb-Pb dating constraints on the accretion and cooling history of chondrites     

Audrey Bouvier  Janne Blichert-Toft  Jeffrey D. Vervoort 《Geochimica et cosmochimica acta》2007,71(6):1583-1604

We have analyzed the Pb isotopic compositions of whole-rocks and various components (CAIs, chondrules, and/or mineral separates) of two carbonaceous chondrites, Allende (CV3) and Murchison (CM2), and nine ordinary chondrites, Sainte Marguerite (H4), Nadiabondi and Forest City (H5), Kernouvé (H6), Bjurböle (L/LL4), Elenovka and Ausson (L5), Tuxtuac (LL5), and Saint-Séverin (LL6) by MC-ICP-MS. Three CAI fractions from Allende define an isochron with an age of 4568.1 ± 9.4 Ma (MSWD = 0.08) and plot on the same isochron as fragments of the Efremovka inclusion E60 analyzed by Amelin et al. [Amelin, Y., Krot, A. N., Hutcheon, I. D., and Ulyanov, A. A. (2002a). Lead isotopic ages of chondrules and calcium-aluminum-rich inclusions. Science297, 1679-1683]. When these two groups of samples are combined, the isochron yields an age of 4568.5 ± 0.5 (MSWD = 0.90), which is our best estimate of the age of the Solar System. Chondrules and pyroxene-olivine fractions from the ordinary chondrites yield ages that reflect the blocking of Pb isotope equilibration with the nebular gas. The combination of these ages with the corresponding metamorphic phosphate ages provides constraints on the thermal history of the different chondrite parent bodies. Among the H chondrites, Sainte Marguerite cooled to below ∼1100 K within a few My at 4565 Ma and to ∼800 K at 4563 Ma. Nadiabondi appears to have experienced a slightly more protracted cooling history with the corresponding interval lasting from 4559 to 4556 Ma. The data from Forest City and Kernouvé show evidence of late-stage perturbation with resulting U/Pb fractionation. Likewise, Pb isotopes in Tuxtuac (LL5) record a cooling history lasting from ∼4555 to 4544 Ma, which may indicate that the cooling history for the LL parent body was more prolonged than for the H parent body. We suggest a thermal evolution model for the growth of the planetary bodies based on the release of radiogenic heat from ²⁶Al and ⁶⁰Fe. This model incorporates the accretion rate, which determines the time at which the radiogenic heat becomes efficiently trapped, and the terminal size of the parent body, which controls its overall thermal inertia. The parent bodies of carbonaceous chondrites, which show little indication of metamorphic transformation, collect cooler nebular material at a relatively late stage. Small asteroids of ∼10-50 km radius accreting within 1-3 My could be the parent bodies of H and LL chondrites. The parent body of the L chondrites is likely to be a larger asteroid (r > 100 km) or possibly the product of collisions of smaller planetary bodies.  相似文献   

The dark side of zircon: textural,age, oxygen isotopic and trace element evidence of fluid saturation in the subvolcanic reservoir of the Island Park-Mount Jackson Rhyolite,Yellowstone (USA)     

Juliana?TrochEmail authorView author&#;s OrcID profile  Ben?S.?Ellis  Axel?K.?Schmitt  Anne-Sophie?Bouvier  Olivier?Bachmann 《Contributions to Mineralogy and Petrology》2018,173(7):54

The Island Park-Mount Jackson series in the Yellowstone volcanic field, Wyoming (USA), is a suite of rhyolitic domes and lavas that erupted between the caldera-forming eruptions of the Mesa Fall Tuff (1.3 Ma) and the Lava Creek Tuff (0.6 Ma). Combined zircon U/Pb geochronology, Raman spectroscopy, oxygen isotopic and trace elemental compositions document storage conditions of these magmas between consecutive supereruptions. Based on comparison with co-erupted melt compositions and textural criteria, four zircon compositional groups are identified that record different stages along a continuous magmatic evolution from trace element-poor rhyolite at high temperatures to extremely fractionated rhyolite where zircon trace elements are highly enriched (e.g., >?1000 ppm U). These latter zircon domains are dark in cathodoluminescence images and show broadened Raman peaks relative to near-endmember zircon, indicating that substitution of non-stoichiometric trace elements into zircon leads to distortion of the crystal lattice. Some of these zircon domains contain inclusions of U-Th-REE-phases, likely originating from coupled dissolution–reprecipitation of metastable trace element-rich zircon in the presence of a fluid phase. Rhyolite-MELTS simulations indicate that at the conditions required to produce the observed enrichment in trace elements, a fluid phase is likely present. These findings illustrate that zircons can be assembled from a variety of co-existing magmatic environments in the same magma reservoir, including near-solidus volatile-rich melts close to the magmatic–hydrothermal transition.  相似文献   

The Monitor project: rotation of low-mass stars in NGC 2362 – testing the disc regulation paradigm at 5 Myr     

Jonathan Irwin  Simon Hodgkin  Suzanne Aigrain  Jerome Bouvier  Leslie Hebb  Mike Irwin  Estelle Moraux 《Monthly notices of the Royal Astronomical Society》2008,384(2):675-686

We report on the results of a time-series photometric survey of NGC 2362, carried out using the CTIO 4-m Blanco telescope and Mosaic-II detector as part of the Monitor project. Rotation periods were derived for 271 candidate cluster members over the mass range  0.1 ≲ M /M_⊙≲ 1.2  . The rotation period distributions show a clear mass-dependent morphology, qualitatively similar to that in NGC 2264, as would be expected from the age of this cluster. Using models of angular momentum evolution, we show that angular momentum losses over the ∼1–5 Myr age range appear to be needed in order to reproduce the evolution of the slowest rotators in the sample from the ONC to NGC 2362, as found by many previous studies. By incorporating Spitzer IRAC mid-infrared (mid-IR) measurements, we found that three to four objects showing mid-IR excesses indicative of the presence of circumstellar discs were all slow rotators, as would be expected in the disc regulation paradigm for early pre-main-sequence angular momentum evolution, but this result is not statistically significant at present, given the extremely limited sample size.  相似文献   

The Meteoritical Bulletin,No. 102          下载免费PDF全文

Alex Ruzicka  Jeffrey Grossman  Audrey Bouvier  Christopher D. K. Herd  Carl B. Agee 《Meteoritics & planetary science》2015,50(9):1662-1662

Meteoritical Bulletin 102 contains 3141 meteorites including 12 falls (Boumdeid (2003), Boumdeid (2011), Braunschweig, Chelyabinsk, Dongyang, Draveil, Heyetang, Indian Butte, Katol, Ladkee, Ouadangou, Xining), with 2611 ordinary chondrites, 264 HED achondrites, 124 carbonaceous chondrites, 30 ureilites, 20 Martian meteorites, 16 primitive achondrites, 16 Rumuruti chondrites, 15 mesosiderites, 12 iron meteorites, 10 lunar meteorites, 9 enstatite chondrites, 4 enstatite achondrites, 4 Pallasites, 4 ungrouped achondrites, and 2 angrites, and with 1708 from Antarctica, 956 from Africa, 294 from South America, 126 from Asia, 47 from North America, 6 from Europe (including Russia), and 4 from Oceania. Information about approved meteorites can be obtained from the Meteoritical Bulletin Database (MBD) available on line at http://www.lpi.usra.edu/meteor/ .  相似文献   

Probing the magnetosphere in young stars with AMBER/VLTI     

C. Dougados  J. Bouvier  G. Duvert  P.J.V. Garcia  D.F.M. Folha 《Astrophysics and Space Science》2003,286(1-2):151-156

The exact geometry of the interface region between the accretion disk and the stellar surface in young stars has crucial implications for both the origin of mass-loss and the regulation of stellar angular momentum. We discuss proposed AMBER/VLTI observations of the Paβ line emitting region that will put the first direct constraints on the magnetospheric accretion flow scenario in active young stellar systems. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Time Dependent Magnetospheric Accretion in T Tauri Stars     

J. Bouvier  C. Dougados  S.H.P. Alencar 《Astrophysics and Space Science》2004,292(1-4):659-664

We review recent observational results which suggest that magnetically channeled accretion in T Tauri stars is a highly time dependent process on timescales ranging from hours to months.  相似文献   

Report of the Science Community Workshop on the proposed First Sample Depot for the Mars Sample Return Campaign     

Prepared by the MSR Campaign Science Group  A. D. Czaja  M.-P. Zorzano  the rest of the MCSG team  with Chairs  G. Kminek  M. A. Meyer  Members  D. W. Beaty  E. Sefton-Nash  B. L. Carrier  F. Thiessen  T. Haltigin  A. Bouvier  N. Dauphas  K. L. French  L. J. Hallis  R. L. Harris  E. Hauber  L. E. Rodriguez  S. P. Schwenzer  A. Steele  K. T. Tait  M. T. Thorpe  T. Usui  J. Vanhomwegen  M. A. Velbel  S. Edwin  K. A. Farley  D. P. Glavin  A. D. Harrington  L. E. Hays  A. Hutzler  M. Wadhwa 《Meteoritics & planetary science》2023,58(6):885-896

The Mars 2020/Mars Sample Return (MSR) Sample Depot Science Community Workshop was held on September 28 and 30, 2022, to assess the Scientifically-Return Worthy (SRW) value of the full collection of samples acquired by the rover Perseverance at Jezero Crater, and of a proposed subset of samples to be left as a First Depot at a location within Jezero Crater called Three Forks. The primary outcome of the workshop was that the community is in consensus on the following statement: The proposed set of ten sample tubes that includes seven rock samples, one regolith sample, one atmospheric sample, and one witness tube constitutes a SRW collection that: (1) represents the diversity of the explored region around the landing site, (2) covers partially or fully, in a balanced way, all of the International MSR Objectives and Samples Team scientific objectives that are applicable to Jezero Crater, and (3) the analyses of samples in this First Depot on Earth would be of fundamental importance, providing a substantial improvement in our understanding of Mars. At the conclusion of the meeting, there was overall community support for forming the First Depot as described at the workshop and placing it at the Three Forks site. The community also recognized that the diversity of the Rover Cache (the sample collection that remains on the rover after placing the First Depot) will significantly improve with the samples that are planned to be obtained in the future by the Perseverance rover and that the Rover Cache is the primary target for MSR to return to Earth.  相似文献   

2013 Leonard Medal for Ahmed El Goresy     

Catherine Caillet  Audrey Bouvier 《Meteoritics & planetary science》2013,48(9):1702-1704

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Characterization of subsurface fluxes at the plot scale during flash floods in the Valescure catchment,France     

Christophe Bouvier  Marko Adamovic  Pierre-Alain Ayral  Pascal Brunet  Jean-François Didon-Lescot  Jean-Marc Domergue  Rosario Spinelli 《水文研究》2021,35(4):e14144

This study focuses on a 10-m² plot within a granitic hillslope in Cevennes mountainous area in France, in order to study infiltration and subsurface hydrological processes during heavy rainfalls and flash floods. The monitoring device included water content at several depths (0–70 cm for the shallow soil water; 0–10 m for the deep water) during both intense artificial and natural rainfall events, chemical and physical tracers, time-lapse electrical resistivity tomography. During the most intense events, the infiltrated water was estimated to be some hundreds of millimetres, which largely exceeds the topsoil capacity (≤40 cm deep in most of the cases). The weathered/fractured rock area below the soil clearly has an active role in the water storage and sub-surface flow dynamics. Vertical flow was dominant in the first 0–10 m, and lateral flow was effective at 8–10 m depth, at the top of the saturated area. The speed of the vertical flow was estimated between 1 and 10 m/hr, whereas it was estimated between 0.1 and 1 m/hr for the lateral flow. The interpretation of the experiments might lead to a local pattern of the 2D-hydrological processes and profile properties, which could be generic for most of the mountainous catchments under Mediterranean climate. It suggests that fast triggering of floods at the catchment scale cannot be explained by a mass transfer within the hillslope, but should be due to a pressure wave propagation through the bedrock fractures, which allows exfiltration of the water downstream the hillslope.  相似文献