A new histogram-free likelihood method applied to simulated JWST observations of brown dwarfs shows that globular cluster ages can be determined with formal errors under 0.2 Gyr.
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New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
Mixed citation behavior. Most common role is background (50%).
abstract
We present new models for low-mass stars down to the hydrogen-burning limit that consistently couple atmosphere and interior structures, thereby superseding the widely used BCAH98 models. The new models include updated molecular linelists and solar abundances, as well as atmospheric convection parameters calibrated on 2D/3D radiative hydrodynamics simulations. Comparison of these models with observations in various colour-magnitude diagrams for various ages shows significant improvement over previous generations of models. The new models can solve flaws that are present in the previous ones, such as the prediction of optical colours that are too blue compared to M dwarf observations. They can also reproduce the four components of the young quadruple system LkCa 3 in a colour-magnitude diagram with one single isochrone, in contrast to any presently existing model. In this paper we also highlight the need for consistency when comparing models and observations, with the necessity of using evolutionary models and colours based on the same atmospheric structures.
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2026 19representative 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.
Planetary formation tracks on the HR diagram show three branches: ascending during solid accretion with L proportional to T to the 8th for in-situ planetesimals, near-horizontal during gas accretion, and descending during post-accretion cooling.
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.
Two long period radio transients are detached white dwarf-M dwarf binaries with matching periods, massive cool crystallized white dwarfs, low inclinations, and an estimated population of 100-2000 such systems within 2 kpc.
High-contrast imaging with PACO and REXPACO reveals a new candidate companion at ~14 au and a tightly wound H-alpha spiral in the inner disk of HD 142527, suggesting ongoing companion-disk interactions.
GJ 1132 b is estimated to have received at least 50 times the cumulative XUV flux of modern Earth with over 95% probability across models, supporting its classification as an atmosphere-free world.
FUor masses inferred from Keplerian line broadening in H-band spectra match the solar neighborhood IMF, indicating a universal eruptive phase during star formation.
Simulations of the Aquila Rift show uneven clumps accreting gas and merging along filaments to form a fractal cluster whose velocity anisotropies, rotation, and expansion record the assembly history even after gas removal.
Sustained mass transfer from a circumbinary disc enables giant planet formation in gamma-Cephei-like binaries by prolonging the lifetime of the circumprimary disc against truncation and photoevaporation.
Atmospheric retrievals yield C/O = 0.57±0.01, [M/H] = 0.18±0.05, and 12CO/13CO ≈ 95 for 2MASS J0249-0557 c, matching benchmark brown dwarfs and favoring star-like gravitational collapse over disk accretion.
An optimal Stokes number window of 0.01-0.03 allows streaming instability to form planetesimals and pebble accretion to build all three main planet classes, with cold gas giants needing the lowest turbulence and largest discs.
TOI-201 has three planets whose co-transiting configuration will end in 200 years due to Kozai-Lidov oscillations driven by mutual inclinations.
Numerical inversion of GJ 486b's escape history shows strong degeneracy between initial hydrogen atmosphere and water inventory, yielding a probabilistic stellar age of 2.90^{+2.47}_{-2.27} Gyr when using a planet-formation prior.
Tier 1 Ariel spectra suffice for sub-1.5 dex constraints on H2O and CO2 in giant-planet atmospheres, with higher tiers providing only incremental gains and more molecules in select cases.
A parameterized accretion disk model for young stellar objects predicts that optical and near-IR outburst light curves track the input accretion rate profile while mid-IR curves respond more to the location and heating of the innermost dust disk.
New observations show a curved jet from FN Tau likely caused by disk precession, associated with past outbursts.
An upgraded planet population synthesis model incorporates post-disc dynamical evolution and atmospheric enrichment to generate synthetic exoplanet populations with improved fidelity to N-body results and observations.
The paper reviews techniques for measuring protostellar accretion, analyzes methodological differences and caveats in comparing observations with simulations, and outlines next steps for a fuller picture.
citing papers explorer
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New Way to Date Globular Clusters: Brown Dwarf Cooling Sequences
A new histogram-free likelihood method applied to simulated JWST observations of brown dwarfs shows that globular cluster ages can be determined with formal errors under 0.2 Gyr.
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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.
-
Planetary formation tracks on the Hertzsprung-Russell diagram: Visualising the processes of giant planet growth
Planetary formation tracks on the HR diagram show three branches: ascending during solid accretion with L proportional to T to the 8th for in-situ planetesimals, near-horizontal during gas accretion, and descending during post-accretion cooling.
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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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White dwarf + M dwarf Detached Binaries in Long Period Radio Transients: Observed Binary Parameters, Evolution, and Population Constraints
Two long period radio transients are detached white dwarf-M dwarf binaries with matching periods, massive cool crystallized white dwarfs, low inclinations, and an estimated population of 100-2000 such systems within 2 kpc.
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Exploration of the inner region of the system HD 142527
High-contrast imaging with PACO and REXPACO reveals a new candidate companion at ~14 au and a tightly wound H-alpha spiral in the inner disk of HD 142527, suggesting ongoing companion-disk interactions.
-
The Range of Cumulative XUV Flux on GJ 1132 b
GJ 1132 b is estimated to have received at least 50 times the cumulative XUV flux of modern Earth with over 95% probability across models, supporting its classification as an atmosphere-free world.
-
The FUor Mass Distribution Matches the Solar Neighborhood IMF: Evidence for a Universal Eruptive Phase
FUor masses inferred from Keplerian line broadening in H-band spectra match the solar neighborhood IMF, indicating a universal eruptive phase during star formation.
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Simulating Star Formation and Star Cluster Assembly in the Aquila Rift Using Archival Observations
Simulations of the Aquila Rift show uneven clumps accreting gas and merging along filaments to form a fractal cluster whose velocity anisotropies, rotation, and expansion record the assembly history even after gas removal.
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A formation pathway for giant planets in S-type discs of {\gamma}-Cephei-like compact binaries
Sustained mass transfer from a circumbinary disc enables giant planet formation in gamma-Cephei-like binaries by prolonging the lifetime of the circumprimary disc against truncation and photoevaporation.
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Chemistry and Isotope Ratios of Substellar Atmospheres in the $\beta$ Pictoris Young Moving Group
Atmospheric retrievals yield C/O = 0.57±0.01, [M/H] = 0.18±0.05, and 12CO/13CO ≈ 95 for 2MASS J0249-0557 c, matching benchmark brown dwarfs and favoring star-like gravitational collapse over disk accretion.
-
Exploring the conditions for forming planetesimals by the streaming instability and planetary systems by pebble accretion
An optimal Stokes number window of 0.01-0.03 allows streaming instability to form planetesimals and pebble accretion to build all three main planet classes, with cold gas giants needing the lowest turbulence and largest discs.
-
Uncovering the Rapidly Evolving Orbits of the Dynamic TOI-201 System
TOI-201 has three planets whose co-transiting configuration will end in 200 years due to Kozai-Lidov oscillations driven by mutual inclinations.
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Inversion of Hydrogen-rich Atmosphere and Water Content for GJ 486b
Numerical inversion of GJ 486b's escape history shows strong degeneracy between initial hydrogen atmosphere and water inventory, yielding a probabilistic stellar age of 2.90^{+2.47}_{-2.27} Gyr when using a planet-formation prior.
-
On the Information Content of Ariel Transmission Spectra: Reassessing the Tier System
Tier 1 Ariel spectra suffice for sub-1.5 dex constraints on H2O and CO2 in giant-planet atmospheres, with higher tiers providing only incremental gains and more molecules in select cases.
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A Parameterized YSO Accretion Disk Model with Increasing Accretion Rate: Predicted Outburst Lightcurves
A parameterized accretion disk model for young stellar objects predicts that optical and near-IR outburst light curves track the input accretion rate profile while mid-IR curves respond more to the location and heating of the innermost dust disk.
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The curved jet in the young star FN Tau
New observations show a curved jet from FN Tau likely caused by disk precession, associated with past outbursts.
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Rapid and Predictive Planet Population Synthesis Model (RAPPS) I. Upgraded model and resulting synthetic populations
An upgraded planet population synthesis model incorporates post-disc dynamical evolution and atmospheric enrichment to generate synthetic exoplanet populations with improved fidelity to N-body results and observations.
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The Accretion Process on Protostars
The paper reviews techniques for measuring protostellar accretion, analyzes methodological differences and caveats in comparing observations with simulations, and outlines next steps for a fuller picture.