Null detection of 0.3-micron artificial grains in 1 m³ lunar regolith excludes Solar-type stars dispersing more than ~0.09 Earth masses of long-lived technomaterial over Galactic history.
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The chemical make-up of the Sun: A 2020 vision
Mixed citation behavior. Most common role is background (50%).
abstract
The chemical composition of the Sun is a fundamental yardstick in astronomy, relative to which essentially all cosmic objects are referenced. We reassess the solar abundances of all 83 long-lived elements, using highly realistic solar modelling and state-of-the-art spectroscopic analysis techniques coupled with the best available atomic data and observations. Our new improved analysis confirms the relatively low solar abundances of C, N, and O obtained in our previous 3D-based studies: $\log\epsilon_{\text{C}}=8.46\pm0.04$, $\log\epsilon_{\text{N}}=7.83\pm0.07$, and $\log\epsilon_{\text{O}}=8.69\pm0.04$. The revised solar abundances for the other elements also typically agree well with our previously recommended values with just Li, F, Ne, Mg, Cl, Kr, Rb, Rh, Ba, W, Ir, and Pb differing by more than $0.05$ dex. The here advocated present-day photospheric metal mass fraction is only slightly higher than our previous value, mainly due to the revised Ne abundance from Genesis solar wind measurements: $X_{\rm surface}=0.7438\pm0.0054$, $Y_{\rm surface}=0.2423\pm 0.0054$, $Z_{\rm surface}=0.0139\pm 0.0006$, and $Z_{\rm surface}/X_{\rm surface}=0.0187\pm 0.0009$. Overall the solar abundances agree well with those of CI chondritic meteorites but we identify a correlation with condensation temperature such that moderately volatile elements are enhanced by $\approx 0.04$ dex in the CI chondrites and refractory elements possibly depleted by $\approx 0.02$ dex, conflicting with conventional wisdom of the past half-century. Instead the solar chemical composition resembles more closely that of the fine-grained matrix of CM chondrites. The so-called solar modelling problem remains intact with our revised solar abundances, suggesting shortcomings with the computed opacities and/or treatment of mixing below the convection zone in existing standard solar models.
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representative citing papers
Two young low-mass stars show solar C/O ratios while their inner disks are hydrocarbon-rich with C/O greater than one, providing direct evidence that disk processes enhance inner-disk carbon.
Native-resolution retrievals on 0.97-5.27 micron JWST spectra of VHS 1256 b find a ~79% cloud deck, solar-like metallicity and C/O, and depleted 18O in a partially cloudy disequilibrium atmosphere.
76 N/O-enhanced galaxies at 4<z<8.5 are observed shortly after starbursts, either in the WR enrichment phase within 10 Myr or the AGB phase after 30-40 Myr following outflows.
Phase-resolved high-resolution spectroscopy of CoRoT-2b measures sub-synchronous rotation at 2.6-sigma significance, consistent with its western hotspot offset.
Synthetic observables from tECSN models show slower early red-color decline due to higher Ti/Cr and a late-time 12.8 μm Ne II line that strengthens over time, unlike comparable CO deflagration models.
Self-consistent spherical accretion simulations show cooling-enhanced growth of PBHs with radiative efficiency ~10^{-2} in the bremsstrahlung regime, yielding a critical seed mass of ~10^{-16} M_sun to consume a solar-mass star in a Hubble time.
Stacked JWST spectra show weak MZR slope evolution to z~5 with declining normalization, steeper MZR beyond z~5, and emerging shallow FMR anti-correlation by z~5.
ROSSINI achieves integral field spectroscopy without IFUs via rotational slitless imaging combined with tomographic reconstruction, recovering input datacubes to percent-level accuracy in numerical simulations.
JWST MIRI MRS observations show the Galactic Center Minispiral gas has 1-2.5 solar metallicity, Wolf-Rayet driven ionization, significant Ni and Fe dust destruction, and harder radiation in compact structures near Sgr A*.
Direct [OIII]4364-based metallicities show that galaxies with stellar masses 10^6.7-9 solar masses at z~6-8 are 0.3-0.5 dex more metal-poor than local galaxies of the same mass, with slope 0.25 and 0.2 dex scatter.
ALMA Band 6 data detect SiO emission and masers up to v=8 in AGB stars, showing clumpy distributions, velocity gradients, and a tentative link between emission radius and mass-loss rate.
Joint speckle-atmosphere retrievals on JWST spectra of HD 19467 B and a field T dwarf detect H2O, CH4, CO, CO2 and NH3, yield carbon isotopic ratios of 154 and 85 respectively, and show near-solar metallicity with subsolar C/O.
Type Ib supernovae are systematically bluer than Type Ic supernovae in optical colors, likely due to helium-rich versus helium-poor progenitors.
Solar tachocline production of symmetrons yields a keV-scale flux at Earth whose absorption in xenon detectors provides new complementary bounds on symmetron parameter space.
Measures a new nebular attenuation curve from 1400-9550 Å for galaxy GOODSN-17940 at z=4.41 that is steeper than Milky Way/SMC/Calzetti at long wavelengths, similar in blue-optical, and shallower in UV with no 2175 Å bump.
New high-redshift empirical T_e-based metallicity calibrations for strong-line ratios derived from direct oxygen abundances in 46 galaxies spanning z=1.4-8.7.
COLIBRE simulations find the galaxy gas-phase MZR already in place at z≈10 with little evolution until z≈5, then shallowens at low z, with high-mass turnover set by AGN feedback and low-mass end by core-collapse supernovae.
The Helix Nebula is a low-density, stratified object with near-solar oxygen abundance (8.7), a ~1 dex sulfur deficit, and moderate helium/nitrogen enrichment placing it near the Type I boundary, with abundance variations attributed to ionization structure rather than chemical inhomogeneity.
New stack-based strong-line calibrations from ~1500 spectra yield mass-metallicity relations at z=1-10 with decreasing metallicity toward higher redshift and no slope change, plus 50 EMPG candidates at 1-4% solar metallicity showing large scatter and opposite sSFR trends.
Population synthesis from binary evolution models predicts periodic neutron star-companion interactions in more than half of surviving hydrogen-poor core-collapse supernovae, with periods peaking at 20-50 days and lasting 0.5-10 years.
New EIS effective area curves confirm factor-of-two long-wavelength degradation without fine structure and reveal inverse FIP bias with Fe/H at 0.57 of photospheric value at 10 MK, confirmed by Chandrayaan-2 SXM spectra.
New empirical calibrations between 19 emission-line ratios and oxygen abundance are derived from direct electron-temperature measurements in 139 star-forming galaxies at z=1.4-10.6.
New high-resolution spectra yield abundances for 7 neutron-capture elements in open cluster stars, revealing flat Milky Way gradients for second-peak s- and r-process species and shallower slopes for first-peak s-process.
citing papers explorer
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Micron-Scale Technosignatures: How a Cubic Metre of Lunar Regolith May Begin to Constrain the Number of Past Technological Civilisations in the Galaxy
Null detection of 0.3-micron artificial grains in 1 m³ lunar regolith excludes Solar-type stars dispersing more than ~0.09 Earth masses of long-lived technomaterial over Galactic history.
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A Chemical Mismatch Between Young Stars and Their Inner Disks
Two young low-mass stars show solar C/O ratios while their inner disks are hydrocarbon-rich with C/O greater than one, providing direct evidence that disk processes enhance inner-disk carbon.
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Native-resolution retrievals of VHS 1256-1257 b spanning the JWST/NIRSpec wavelength range: Chemical composition of a partially cloudy atmosphere
Native-resolution retrievals on 0.97-5.27 micron JWST spectra of VHS 1256 b find a ~79% cloud deck, solar-like metallicity and C/O, and depleted 18O in a partially cloudy disequilibrium atmosphere.
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Diverse Histories and Common Origins of Nitrogen-enhanced JWST Galaxies
76 N/O-enhanced galaxies at 4<z<8.5 are observed shortly after starbursts, either in the WR enrichment phase within 10 Myr or the AGB phase after 30-40 Myr following outflows.
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Unraveling the Mystery of the Peculiar and Young Hot Jupiter CoRoT-2b II: Phase Resolved Emission Spectroscopy with VLT/CRIRES+ and Gemini-S/IGRINS
Phase-resolved high-resolution spectroscopy of CoRoT-2b measures sub-synchronous rotation at 2.6-sigma significance, consistent with its western hotspot offset.
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Observational signatures of thermonuclear electron-capture supernovae -- Ne II line strengthening and color evolution as traces of the explosion mechanism
Synthetic observables from tECSN models show slower early red-color decline due to higher Ti/Cr and a late-time 12.8 μm Ne II line that strengthens over time, unlike comparable CO deflagration models.
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Accretion of Primordial Black Holes in Stellar Interiors
Self-consistent spherical accretion simulations show cooling-enhanced growth of PBHs with radiative efficiency ~10^{-2} in the bremsstrahlung regime, yielding a critical seed mass of ~10^{-16} M_sun to consume a solar-mass star in a Hubble time.
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The JADES Mass-Metallicity and Fundamental Metallicity Relations at $z\gtrsim2$ Using New High-Redshift Metallicity Calibrations
Stacked JWST spectra show weak MZR slope evolution to z~5 with declining normalization, steeper MZR beyond z~5, and emerging shallow FMR anti-correlation by z~5.
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Integral field spectroscopy with no IFUs: combining wide-field rotational slitless spectroscopy with tomographic reconstruction
ROSSINI achieves integral field spectroscopy without IFUs via rotational slitless imaging combined with tomographic reconstruction, recovering input datacubes to percent-level accuracy in numerical simulations.
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Ionization Structure and Metal Enrichment of the Galactic Center Minispiral Observed with JWST
JWST MIRI MRS observations show the Galactic Center Minispiral gas has 1-2.5 solar metallicity, Wolf-Rayet driven ionization, significant Ni and Fe dust destruction, and harder radiation in compact structures near Sgr A*.
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A Glimpse of the Low-Mass End of the Direct Mass-Metallicity Relation at $z\sim6-8$
Direct [OIII]4364-based metallicities show that galaxies with stellar masses 10^6.7-9 solar masses at z~6-8 are 0.3-0.5 dex more metal-poor than local galaxies of the same mass, with slope 0.25 and 0.2 dex scatter.
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ATOMIUM: Inner circumstellar envelopes of oxygen-rich AGB stars as revealed by highly excited SiO lines
ALMA Band 6 data detect SiO emission and masers up to v=8 in AGB stars, showing clumpy distributions, velocity gradients, and a tentative link between emission radius and mass-loss rate.
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JWST high-contrast spectroscopy with speckle modelling: Atmospheric retrievals of the T dwarf companion HD 19467 B
Joint speckle-atmosphere retrievals on JWST spectra of HD 19467 B and a field T dwarf detect H2O, CH4, CO, CO2 and NH3, yield carbon isotopic ratios of 154 and 85 respectively, and show near-solar metallicity with subsolar C/O.
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Type Ib Supernovae are bluer than Type Ic Supernovae
Type Ib supernovae are systematically bluer than Type Ic supernovae in optical colors, likely due to helium-rich versus helium-poor progenitors.
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Probing Solar Symmetrons with Direct Detection
Solar tachocline production of symmetrons yields a keV-scale flux at Earth whose absorption in xenon detectors provides new complementary bounds on symmetron parameter space.
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The AURORA Survey: The Nebular Attenuation Curve of a Galaxy at z=4.41 from Ultraviolet to Near-Infrared Wavelengths
Measures a new nebular attenuation curve from 1400-9550 Å for galaxy GOODSN-17940 at z=4.41 that is steeper than Milky Way/SMC/Calzetti at long wavelengths, similar in blue-optical, and shallower in UV with no 2175 Å bump.
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Direct T_e-based Metallicities of z=2-9 Galaxies with JWST/NIRSpec: Empirical Metallicity Calibrations Applicable from Reionization to Cosmic Noon
New high-redshift empirical T_e-based metallicity calibrations for strong-line ratios derived from direct oxygen abundances in 46 galaxies spanning z=1.4-8.7.
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The evolution of the galaxy gas-phase mass-metallicity relation from $z=15$ to $z=0$ in the COLIBRE cosmological simulations
COLIBRE simulations find the galaxy gas-phase MZR already in place at z≈10 with little evolution until z≈5, then shallowens at low z, with high-mass turnover set by AGN feedback and low-mass end by core-collapse supernovae.
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SDSS-V LVM: Revealing the Physical and Chemical Structure of the Helix Nebula
The Helix Nebula is a low-density, stratified object with near-solar oxygen abundance (8.7), a ~1 dex sulfur deficit, and moderate helium/nitrogen enrichment placing it near the Type I boundary, with abundance variations attributed to ionization structure rather than chemical inhomogeneity.
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JADES: the mass-metallicity relation at $z=1-10$. New calibrations, extremely metal-poor galaxies, and chemical diversity
New stack-based strong-line calibrations from ~1500 spectra yield mass-metallicity relations at z=1-10 with decreasing metallicity toward higher redshift and no slope change, plus 50 EMPG candidates at 1-4% solar metallicity showing large scatter and opposite sSFR trends.
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Neutron star-companion interaction in core collapse supernovae. Population synthesis based on detailed binary evolution models
Population synthesis from binary evolution models predicts periodic neutron star-companion interactions in more than half of surviving hydrogen-poor core-collapse supernovae, with periods peaking at 20-50 days and lasting 0.5-10 years.
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Modeling Flare Continuum Emission Observed by Hinode/EIS: Instrument Calibration and Element Composition Results
New EIS effective area curves confirm factor-of-two long-wavelength degradation without fine structure and reveal inverse FIP bias with Fe/H at 0.57 of photospheric value at 10 MK, confirmed by Chandrayaan-2 SXM spectra.
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The AURORA Survey: High-Redshift Empirical Metallicity Calibrations from Electron Temperature Measurements at z=2-10
New empirical calibrations between 19 emission-line ratios and oxygen abundance are derived from direct electron-temperature measurements in 139 star-forming galaxies at z=1.4-10.6.
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OCCAM X. Neutron Capture Abundances with Keck/HIRES & Magellan/MIKE
New high-resolution spectra yield abundances for 7 neutron-capture elements in open cluster stars, revealing flat Milky Way gradients for second-peak s- and r-process species and shallower slopes for first-peak s-process.
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The HST/WFC3 Transmission Spectrum of AU Mic b Part I: An Atmosphere Obscured by Contamination and Systematics
The transmission spectrum of AU Mic b is dominated by the transit light source effect from stellar spots, yielding only weak atmospheric constraints with a preferred scale height below 185 km.
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JWST Absorption-Line Analysis of UV-Bright Galaxies at $z=7.2-10.6$: Early Chemical Enrichment Traced by C, O, Mg, Al, Si, and Fe
JWST spectra reveal that two z~7 galaxies already show near-solar iron-to-silicon ratios with no strong odd-even effect, favoring early Type Ia supernovae over pair-instability supernovae as the source of iron enrichment.
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Next-generation Exo-REM atmospheric models: application to VHS 1256 b to emulate patchy clouds
Exo-REM k26 grids with f_sed and a two-column patchy-cloud framework fit VHS 1256 b with a 60-40 thick-thin split and reproduce the 10 μm silicate feature.
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A Systematic NLTE Study of Very Metal-Poor Stars with Metallicity Down to $-4.3$ dex. II. Lithium Abundance and New Insight to the Lithium Plateau
NLTE study finds Spite Plateau extends to lower metallicities with positive slope and identifies lithium plateau in lower red giant branch stars at A(Li)=1.13 dex.
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Testing the reliability of magnetic field strength measurements for M dwarfs
Synthetic spectra tests show Zeeman broadening recovers M dwarf magnetic field strengths more reliably with joint abundance fitting and WAIC selection than with free line strengths or BIC/AIC, which underestimate by 30-50% in active cases.
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Introducing the Lumina project: large-volume radiation-hydrodynamic simulations of the epochs of hydrogen and helium reionization
Lumina runs a 500 cMpc radiation-hydrodynamic simulation combining IllustrisTNG galaxy formation with six-bin M1 radiation transport to predict late stellar-driven HI reionization ending around z=4.75 and AGN-driven HeII reionization nearly complete by z=3.
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Chemistry and Isotope Ratios of Substellar Atmospheres in the $\beta$ Pictoris Young Moving Group and Vicinity
Atmospheric retrievals on CRIRES+ spectra of 2MASS J0249-0557 c and two eta Pic YMG brown dwarfs give solar-like C/O, metallicity, and carbon isotope ratios, supporting gravitational collapse formation for the companion.
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Oxygen Isotopic Compositions of Chondrules as Probes of Solar Protoplanetary Disk Formation
Disk formation simulations reproduce carbonaceous chondrule oxygen isotopes with moderate radial infall or ice-depleted parental clouds, but ordinary chondrules inside the snow line remain difficult to explain under the modeled conditions.
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A Theoretical Study of the Structure and Elemental Abundances of HD 20794
MESA grid models find HD 20794 is a 0.80 solar-mass star aged ~9 Gyr whose observed abundances match core-collapse supernova enrichment and are preserved over Gyr timescales.
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The First Infrared Portrait of A Solar-Like Host Star with Debris Disk: Pioneering High-Resolution H- and K-Band Spectroscopy of HD115617 with Comparative Optical Spectrum Analysis
The first NIR high-resolution spectroscopy of solar analog HD115617 shows a 250 K temperature discrepancy with optical data but confirms solar composition, main-sequence status, and no chemical signature of planetary formation.
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SDSS-V LVM: Verifying what, and where, the 'Galactic Center' Lobe is
The Galactic Center Lobe is a foreground HII region at ~2 kpc, photoionized and forming a closed outer loop, not a Galactic center feature.
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Distinct First-to-Second Peak Yield Ratios and Timescales Reveal a Sub-dominant Prompt Channel
A one-zone model shows that observed [Y/Eu] and [Sr/Eu] trends require a prompt first-peak channel, delayed BNS mergers dominating Eu, and delayed AGB s-process with t_min > 0.3 Gyr.
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Constructing Earth Formation History Using Deep Mantle Noble Gas Reservoirs
Simulations tie the deep-mantle primordial neon reservoir to an initial embryo mass of ~0.3 Earth masses assembled during solar-nebula dispersal.
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Chemical Abundances of the Bioessential Elements C, O and S, and the Refractory Elements Fe and Ni, in Solar-type Exoplanet-hosting Stars from HARPS North and South
Observational study of 290 exoplanet-host stars finds higher C, O, S, Fe, Ni abundances in giant-planet hosts than small-planet hosts, with C/O ratios, hot/warm differences, and mass correlations that vary by subpopulation.
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The ESO SupJup Survey XI. Atmospheric properties of six isolated M- and L-type dwarfs with CRIRES+
Retrievals on six isolated brown dwarfs yield near-solar C/O (0.51-0.63), metallicities, and 12C/13C ratios (91-155) supporting molecular cloud fragmentation origin.
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The Barnard's Star Planetary System: Stability, Composition, and Evolution of Four Sub-Earth Exoplanets
Barnard's Star planets have masses 0.19-0.84 M_earth, are tidally locked, unlikely to retain primary atmospheres, and possess mantles rich in ferropericlase with less than half Earth's water capacity and radiogenic heating.
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Comparative Study of Two Luminous Red Novae I. Progenitor Modeling and Dust Formation
Binary evolution modeling constrains donor masses of 14-23 solar masses for two luminous red novae and shows dust masses are 1-5 orders of magnitude below total ejected envelope masses.
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The Roasting Marshmallows Program with IGRINS on Gemini South V: Atmosphere of MASCARA-1b is Enriched in Refractory Elements
MASCARA-1b atmosphere has solar metallicity, solar C/O, 2.5x solar refractories, and 2.3x solar refractory-to-volatile ratio, consistent with accretion between soot-H2O and H2O-CO snowlines.
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gr8stars II : judgement day for spectroscopic parameter model systematics
Multi-method spectroscopic analysis of 585 FGK dwarfs shows parameter scatters larger than internal errors, inducing sub-5% fractional uncertainties on derived exoplanet radius and mass.
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Observational Signatures and Constraints on the Intermediate Neutron-Capture Process. The Case of the CEMP star TYC 6044-714-1 (RAVE J094921.8-161722)
High-precision analysis of TYC 6044-714-1 favors s+r nucleosynthesis over i-process models, which require implausible conditions and mismatch Ba isotopes.
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ENGRAVE follow-up of a type IIb supernova spatially coincident with the sub-threshold gravitational wave trigger S250818k
SN2025ulz is a type IIb supernova whose shock-cooling tail mimicked a kilonova, demonstrating a key contaminant for gravitational-wave counterpart searches.
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Solar Axions from Nuclear Transitions
Solar axion fluxes from 57Fe and 83Kr nuclear transitions differ by three orders of magnitude, yielding stronger constraints on |g_aN^eff × g_aγγ| and g_aγγ vs. m_a from Chandrayaan-2 XSM data for iron.
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NuFit-6.0: Updated global analysis of three-flavor neutrino oscillations
Updated global analysis finds well-determined neutrino mixing parameters with nearly equal preference for normal and inverted mass orderings in the full dataset.
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Tracing the s-Process: Spectroscopic Insights into Chemical Abundances in O- and C-rich Evolved Stars
Spectroscopic abundances of s-elements in AGB stars provide important constraints on theoretical models of stellar nucleosynthesis and mixing.