Related papers: Testing the chondrule-rich accretion model for pla…
Organic macromolecular matter is the dominant carrier of volatile elements such as carbon, nitrogen, and noble gases in chondrites -- the rocky building blocks from which Earth formed. How this macromolecular substance formed in space is…
We use our new stellar population models, which include effects from variable element abundance ratios, to model the Ca4227 absorption line indices of early-type galaxies (Trager et al.), and to derive calcium element abundances. We find…
Earth's interior, I posit, is like one of the rare, oxygen-starved "enstatite chondrite" meteorites (and unlike a more-oxidized "ordinary chondrite" as has been believed for seventy years). Laboratory-analyzed enstatite-chondrite samples…
Studies of the water content and isotopic composition of water-rich asteroids and comets are of key interest for understanding the late accretion stage of the Solar System cometary and chondritic materials. The PRobe far-infrared Mission…
Cosmochemical studies have proposed that Earth accreted roughly 5-10% of its mass from carbonaceous (CC) material, with a large fraction delivered late via its final impactor, Theia (the Moon-forming impactor). Here, we evaluate this idea…
[Abridged] Combining a time-dependent astrochemical model with a model of planet formation and migration, we compute the carbon-to-oxygen ratio (C/O) of a range of planetary embryos starting their formation in the inner solar system (1-3…
Though ~10 Earth mass rocky/icy cores are commonly held as a prerequisite for the formation of gas giants, theoretical models still struggle to explain how these embryos can form within the lifetimes of gaseous circumstellar disks. In…
Aspects of our Solar System's formation are deduced from observations of the chemical nature of matter. Massive cores are indicative of terrestrial-planet-composition-similarity to enstatite chondrite meteorites, whose highly-reduced state…
We developed an experimental setup to test the hypothesis that accretionary dust rims around chondrules formed in the solar nebula at elevated temperatures. Our experimental method allows us to form dust rims around chondrule-analogs while…
The study of planetesimal debris accreted by white dwarfs offers unique insights into the composition of exoplanets. Using far-ultraviolet and optical spectroscopy, we have analysed the composition of planetesimals accreted by three metal…
Evidence is now compelling that most externally-polluted white dwarfs derive their heavy atoms by accretion from asteroids - the building blocks of rocky planets. Optical and ultraviolet spectroscopy of a small sample of suitable white…
We report Keck High Resolution Echelle Spectrometer data and model atmosphere analysis of two helium-dominated white dwarfs, PG1225-079 and HS2253+8023, whose heavy pollutions most likely derive from the accretion of terrestrial-type…
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…
Elemental and isotopic abundances are the fossils of galactic archaeology. The observed [X/Fe]-[Fe/H] relations in the Galactic bulge and disk and the mass-metallicity relation of galaxies are roughly reproduced with chemodynamical…
The timing of formation for the first planetesimals determines the mode of planetary accretion and their geophysical and compositional evolution. Astronomical observations of circumstellar discs and Solar System geochronology provide…
Planets form from the same cloud of molecular gas and dust as their host stars. Confirming if planetary bodies acquire the same refractory element composition as their natal disc during formation, and how efficiently volatile elements are…
Ca-Al-rich inclusions (CAIs) are the oldest dated solid materials in the solar system, found as light-coloured crystalline ingredients in meteorites. Their formation time is commonly associated with age zero of the Solar System. Yet, the…
Interstellar objects provide the only directly observable samples of icy planetesimals formed around other stars, and can therefore provide insight into the diversity of physical and chemical conditions occurring during exoplanet formation.…
We present evidence that stars with planets exhibit statistically significant silicon and nickel enrichment over the general metal-rich population. We also present simulations which predict silicon enhancement of planet hosts within the…
The bulk volatile contents of chondritic meteorites provide clues to their origins. Matrix and chondrules carry differing abundances of moderately volatile elements, with chondrules carrying a refractory signature. At the high temperatures…