J/ApJ/748/L25ivo://CDS.VizieR/J/ApJ/748/L25doi:10.26093/cds/vizier.17489025CDSWielandt D.Nagashima K.Krot A.N.Huss G.R.Ivanova M.A.Bizzarro M.2017-12-15T10:54:57Z2013-11-29T15:03:57ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frchemical-abundancesatomic-physicscometssolar-systemBeryllium-10 is a short-lived radionuclide (t_1/2_=1.4Myr) uniquely synthesized by spallation reactions and inferred to have been present when the solar system's oldest solids (calcium-aluminum-rich inclusions, CAIs) formed. Yet, the astrophysical site of ^10^Be nucleosynthesis is uncertain. We report Li-Be-B isotope measurements of CAIs from CV chondrites, including CAIs that formed with the canonical ^26^Al/^27^Al ratio of ~5x10^-5^ (canonical CAIs) and CAIs with Fractionation and Unidentified Nuclear isotope effects (FUN-CAIs) characterized by ^26^Al/^27^Al ratios much lower than the canonical value. Our measurements demonstrate the presence of four distinct fossil ^10^Be/^9^Be isochrons, lower in the FUN-CAIs than in the canonical CAIs, and variable within these classes. Given that FUN-CAI precursors escaped evaporation-recondensation prior to evaporative melting, we suggest that the ^10^Be/^9^Be ratio recorded by FUN-CAIs represents a baseline level present in presolar material inherited from the protosolar molecular cloud, generated via enhanced trapping of galactic cosmic rays. The higher and possibly variable apparent ^10^Be/^9^Be ratios of canonical CAIs reflect additional spallogenesis, either in the gaseous CAI-forming reservoir, or in the inclusions themselves: this indicates at least two nucleosynthetic sources of ^10^Be in the early solar system. The most promising locale for ^10^Be synthesis is close to the proto-Sun during its early mass-accreting stages, as these are thought to coincide with periods of intense particle irradiation occurring on timescales significantly shorter than the formation interval of canonical CAIs.2012ApJ...748L..25Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/748/L25CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/743/140 : Abundances (Be,{alpha}) in metal-poor stars (Boesgaard+, 2011)J/A+A/319/593 : [Be] abundances in low-metallicity stars (Molaro+ 1997)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/748/L25https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/748/L25http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/748/L25https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/748/L25https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/748/L25http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/748/L25GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/748/L25/table1Li-Be-B isotope and concentration datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCAIThe calcium-aluminum-rich inclusion namemeta.id;meta.maincharSampleSample identifier (mel=melilite, px=pyroxene)meta.id;src.samplecharf_Sample[cf] coarse- or fine-grained regionmeta.codecharLi[0.5/264] The Li abundance (1)phys.abundfloate_LiUncertainty in Listat.errorfloatBe[13.5/1677] The Be abundance (1)phys.abundfloate_BeUncertainty in Bestat.errorfloatB[0.2/5929] The B abundance (1)phys.abundfloate_BUncertainty in Bstat.errorfloat9Be/6Li[12/7031] Ratio of ^9^Be to ^6^Li abundancephys.abundfloate_9Be/6LiUncertainty in 9Be/6Listat.errorfloat7Li/6Li[9/13] Ratio of ^7^Li to ^6^Li abundancephys.abundfloate_7Li/6LiUncertainty in 7Li/6Listat.errorfloat9Be/11B[0.04/2048] Ratio of ^9^Be to ^11^B abundancephys.abundfloate_9Be/11BUncertainty in 9Be/11Bstat.errorfloat10B/11B[0.2/0.9] Ratio of ^10^B to ^11^B abundancephys.abundfloate_10B/11BUncertainty in 10B/11Bstat.errorfloatJ/ApJ/748/L25/table2Summary of Be/B and 1/B regressionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCAIThe calcium-aluminum-rich inclusion namemeta.id;meta.maincharprimaryNSimbad column added by the CDSmeta.numberintnullablen[5/12] Sample sizemeta.numberint10Be/9Be[2.75/6.7] Ratio of ^10^Be to ^9^Be abundancephys.abundfloate_10Be/9Be[0.2/1.4] 10Be/9Be uncertaintystat.errorfloat10B/11B[0.2427/0.2544] Ratio of ^10^B to ^11^B abundance (Be/B regression)phys.abundfloate_10B/11B[0.0006/0.006] 10B/11B uncertaintystat.errorfloatMSWD[0.52/1.19] Be/B mean square of weighted deviationstat.stdevfloat1/B[0.005/4] 1/B slope (1)stat.correlationfloate_1/B[0.0007/1.8] 1/B uncertainty (1)stat.errorfloat10B/11B2[0.24/0.273] Ratio of ^10^B to ^11^B abundance (1/B regression) (1)phys.abundfloate_10B/11B2[0.0006/0.021] 10B/11B2 uncertainty (1)stat.errorfloatMSWD2[0.4/28] 1/B mean square of weighted deviation (1)stat.stdevfloat