First mid-IR transmission spectrum of TOI-270 d shows molecular features with Bayesian evidence ln B = 2.8-5.3 and identifies candidate trace molecules from an agnostic search of 203 species.
Overcoming the limitations of the energy-limited approximation for planet atmospheric escape
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
Studies of planetary atmospheric composition, variability, and evolution require appropriate theoretical and numerical tools to estimate key atmospheric parameters, among which the mass-loss rate is often the most important. In evolutionary studies, it is common to use the energy-limited formula, which is attractive for its simplicity but ignores important physical effects and can be inaccurate in many cases. To overcome this problem, we consider a recently developed grid of about 7000 one-dimensional upper-atmosphere hydrodynamic models computed for a wide range of planets with hydrogen-dominated atmospheres from which we extract the mass-loss rates. The grid boundaries are [1:39] MEARTH in planetary mass, [1:10] REARTH in planetary radius, [300:2000] K in equilibrium temperature, [0.4:1.3] MSUN in host star's mass, [0.002:1.3] au in orbital separation, and about [10^{26}:5*10^{30}] erg/s in stellar X-ray and extreme ultraviolet luminosity. We then derive an analytical expression for the atmospheric mass-loss rates based on a fit to the values obtained from the grid. The expression provides the mass-loss rates as a function of planetary mass, planetary radius, orbital separation, and incident stellar high-energy flux. We show that this expression is a significant improvement to the energy-limited approximation for a wide range of planets. The analytical expression presented here enables significantly more accurate planetary evolution computations without increasing computing time.
fields
astro-ph.EP 4years
2026 4representative citing papers
Water- and metal-rich atmospheres on compact hot mini-Neptunes lose mass more slowly than H/He cases at high enrichment levels due to enhanced cooling and higher mean molecular weight.
New 2025 transit timing for HIP 41378 f confirms large TTVs and is combined with prior data on planets d and e in an N-body model to update ephemerides and predict future transits.
Reanalysis of TOI-1272 and TOI-1694 retracts TOI-1272 c as planetary, attributes the signal to stellar activity via Gaussian process modeling, and refines orbital parameters for the systems.
citing papers explorer
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The Mid-Infrared Transmission Spectrum of the Temperate Sub-Neptune TOI-270 d
First mid-IR transmission spectrum of TOI-270 d shows molecular features with Bayesian evidence ln B = 2.8-5.3 and identifies candidate trace molecules from an agnostic search of 203 species.
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Escape of Water- and Metal-enriched Atmospheres from compact Hot mini-Neptunes with CHAIN
Water- and metal-rich atmospheres on compact hot mini-Neptunes lose mass more slowly than H/He cases at high enrichment levels due to enhanced cooling and higher mean molecular weight.
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Observing a 542-day transiting giant with large TTVs: The 2025 transit of HIP 41378 f and new constraints on the outer system
New 2025 transit timing for HIP 41378 f confirms large TTVs and is combined with prior data on planets d and e in an N-body model to update ephemerides and predict future transits.
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The GAPS Programme at TNG LXXIV. A reanalysis of the planetary systems TOI-1272 and TOI-1694 with HARPS-N and retraction of the planetary interpretation of TOI-1272 c
Reanalysis of TOI-1272 and TOI-1694 retracts TOI-1272 c as planetary, attributes the signal to stellar activity via Gaussian process modeling, and refines orbital parameters for the systems.