[astro-ph.EP] Sub-Neptunes are the most common short-period (P<100 d) planets known. A major goal for the field is to build a comprehensive understanding of their compositions and evolutionary histories, and […]
photoevaporation
Posted inExoplanets, -moons, -comets
JWST Reveals A Race Against Time For Forming Planets
[SETI Institute] Planets form from disks of gas and dust around young stars, but the gas needed for growth does not last forever. New observations from NASA’s James Webb Space […]
![Reflation events (red) occur across a range of ages and with different magnitudes across the evolution of irradiated super-Earths. The plot shows the normalised bulk density evolution of individual simulations, versus the time elapsed since planet formation. The red lines indicate cases where a reflation event occurs, while blue lines indicate those where it does not occur. The evolution tracks that end with a dot indicate the planet has reached an airless state and complete atmospheric erosion by hydrodynamic escape has taken place. The evolution of the two select cases for Figure 1 are highlighted and denoted with a R and D. These cases illustrate in more detail a representative reflation (red) and deflation case (blue). -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Reflation.png?resize=1200%2C717&ssl=1)
Posted inAstrogeology
Reflation: Redox-driven Atmospheric Inflation As Tracer Of Super-Earth Geochemistry
[astro-ph.EP] We demonstrate that the redox-sensitivity of mantle outgassing can trigger transient episodes of atmospheric re-inflation in highly irradiated and geochemically-reduced super-Earths, a mechanism we term reflation.
Posted inAstronomy & Telescopes, Exploration Gear & Tech, Press Release
The Mass of TOI-1883 b: A Low Density Super-Neptune In The Ridge Regime Transiting An Early-M dwarf
Recent large-scale transit surveys conducted by space telescopes such as Kepler and TESS have revealed a vast number of exoplanets, uncovering the diversity of their population.
Posted inAtmospheres, Climate, Weather, Exoplanets, -moons, -comets, Status Report
Stringent Upper Bounds on Atmospheric Mass Loss from Three Neptune-Sized Planets in the TOI-4010 System
Photoevaporative models predict that the lower edge of the Neptune desert is sculpted by atmospheric mass loss.
Posted inAtmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
The Impact Of Organic Hazes And Graphite On The Observation Of CO2-rich Sub-Neptune Atmospheres
Many sub-Neptune and super-Earth exoplanets are expected to develop metal-enriched atmospheres due to atmospheric loss processes such as photoevaporation or core-powered mass loss.
Posted inExoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report
The TOI-1117 Multi-planetary System: 3 Sub-Neptunes, 1 In Both The Neptunian Desert And Radius Valley
We present the discovery of three sub-Neptune planets around TOI-1117, a Sun-like star with mass 0.97±0.02M⊙, radius 1.05±0.03R⊙, age 4.42±1.50 Gyr and effective temperature 5635±62 K. Light curves from TESS […]
Posted inAstronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
An Eccentric Sub-Neptune Moving Into the Evaporation Desert
Though missions such as Kepler, K2, and TESS have discovered >2,000 sub-Neptune and Neptunian planets, there is a dearth of such planets at close-in (P≲3 days) orbits.
Posted inAstrochemistry, Astrogeology, Exoplanets, -moons, -comets, Status Report
How External Photoevaporation Changes The Inner Disc’s Chemical Composition
Stars mostly form in clusters where neighboring stars can influence proto-planetary disc evolution. Besides gravitational interactions, external photoevaporation can shape these discs. Depending on the strength of photoevaporation, discs can […]
Posted inAtmospheres, Climate, Weather, Status Report
The Diffusion Limit Of Photoevaporation In Primordial Planetary Atmospheres
Photoevaporation is thought to play an important role in the early planetary evolution. In this study, we investigate the diffusion limit of X-ray and ultraviolet induced photoevaporation in primordial atmospheres.