The giant planet-metallicity correlation revealed that planetary formation depends on the stellar properties. There is growing evidence that it is also valid for smaller hot planets, but it is not […]
metallicity
Posted inAstrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report
APEX Survey Of Interstellar HCl: 35Cl/37Cl Isotopic Ratios In Dense Cores And Outflows
Despite being only the 19th most abundant element in the interstellar medium, chlorine’s reactivity and volatility give rise to a unique interstellar chemistry, favouring the formation of several chlorine-bearing hydrides.
Posted inAstrochemistry, Astrogeology, Exoplanets, -moons, -comets, Space Weather & Heliophysics, Status Report, Stellar Cartography, Water/Hycean Worlds & Oceanography
Stellar Chemistry And Planet Size: Insights From GALAH DR4
The well-known correlation between stellar metallicity and planet occurrence is strongest for giant planets, but weaker for smaller planets, suggesting that detailed elemental patterns beyond [Fe/H] may be relevant.
Posted inAstrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Press Release
New Study Sheds Light On The Milky Way’s Mysterious Chemical History
Clues about how galaxies like our Milky Way form and evolve and why their stars show surprising chemical patterns have been revealed by a new study.
Posted inAstrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report
A Window For Water-hydrogen Demixing On Warm Metal-rich Sub-Neptunes
Sub-Neptunes represent the largest exoplanet demographic, yet their bulk compositions remain poorly understood.
![(a) Normalized age distributions p(τ | [Fe/H]) for single stars, binned in [Fe/H] and smoothed using Gaussian filtering. Each vertical slice is normalized by its peak value. The blue line marks the peak age in each bin. Colored points show planet-hosting stars, classified by guiding-center radius Rg: inner (Rg < 7.2 kpc), local (7.2 ≤ Rg ≤ 9.2 kpc), and outer (Rg > 9.2 kpc). (b) Same as (a), but for [α/Fe] instead of [Fe/H]. -- astro-ph.SR](https://i0.wp.com/astrobiology.com/wp-content/uploads/2025/10/Insights-into-Planet-Formation-from.png?resize=1200%2C714&ssl=1)
Posted inExoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release, Stellar Cartography
Insights Into Planet Formation From The Ages, Masses, and Elemental Abundances of Host Stars
How planetary systems form and evolve is a key question in astronomy. Revealing how host star properties, such as elemental abundances, age, and mass, differ from those of non-host stars, […]
![(a) Top panel shows [Eu/α] independent of the temperature bias as a function of [α/H]. Small orange triangles represent data from DM and small green triangles represent data from BB. The cross matched sample of 68 stars described in Section 3.1 is shown in big red squares. Stars from the solar twins analysis by Spina et al. (2018), Bedell et al. (2018) are shown as big blue circles. A black star is used to represent the solar abundance value. The red dashed line at [Eu/α] = 0.06 represents the critical value for an extended dynamo failure given by the model from Nimmo et al. (2020). Outliers in [Eu/H] abundances discussed in Section 6.2 are outlined in black. -- astro-ph.SR](https://i0.wp.com/astrobiology.com/wp-content/uploads/2025/10/Distribution-of-Europium.png?resize=1200%2C711&ssl=1)
Posted inAstrochemistry, Biophysics, Biosignatures & Paleobiology, Habitable Zones, Interstellar, Status Report, Stellar Cartography
Distribution of Europium in The Milky Way Disk; Its Connection to Planetary Habitability and The Source of The R-Process
The energy provided in the radioactive decay of thorium (Th) and uranium (U) isotopes, embedded in planetary mantles, sustains geodynamics important for surface habitability such as the generation of a […]
Posted inAstrochemistry, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Space Weather & Heliophysics, Status Report
Modelling The Effect Of Stellar Metallicity On The XUV Evolution Of Low-mass Stars and its Impact on Exoplanet Atmospheres/habitability
Understanding how exoplanet atmospheres evolve is a key question in the context of habitability. One key process governing this evolution is atmospheric evaporation by stellar X-ray and EUV emission (collectively, […]
Posted inAstrobiology (general), Astrochemistry, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report
Transition Metal Abundance As A Key Parameter For The Search Of Life In The Universe
The search for Life in the Universe generally assumes three basic life’s needs: I) building block elements (i.e., CHNOPS), II) a solvent to life’s reactions (generally, liquid water) and III) […]
![PAH fraction anti-correlates with log([S iii]/[S ii]) (ionization parameter tracer) for thousands H ii regions in 42 PHANGS-JWST galaxies. Panel (a, b) shows all ∼ 17200 analyzed H ii regions, while ∼ 5600 brightest “resolved” H ii regions are shown on Panels (c, d). The dashed red line shows the best-fit linear regression to the “resolved” sample defined by Eq. 4. Histograms on panels (b, d) show how the logarithmic residuals after subtracting this linear trend depend on metallicity. Color on panels (a, c) denotes gas-phase oxygen abundance; red contours show the probability density of the high-metallicity (12 + log(O/H) > 8.2) points (levels correspond to 50, 65, 80, 95 and 99 percentile intervals). The Spearman correlation coefficient (ρ) and RMS scatter around the linear fit are reported on panels (a, c). -- astro-ph.GA](https://i0.wp.com/astrobiology.com/wp-content/uploads/2025/09/Polycyclic-aromatic-hydrocarbons-destruction.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report
Polycyclic Aromatic Hydrocarbons Destruction In Star-forming Regions Across 42 Nearby Galaxies
Polycyclic aromatic hydrocarbons (PAHs) are widespread in the interstellar medium (ISM) of Solar metallicity galaxies, where they play a critical role in ISM heating, cooling, and reprocessing stellar radiation.