![Wavelength distributions of candidate spectral lines retained at each step of the line-selection procedure. The histograms show the initial linelist (light), lines retained after automated vetting (intermediate), and the final manually vetted sample (dark). The shaded background regions indicate approximate wavelength ranges for the Y, J, H, and K-bands.-- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Elemental.png?resize=1200%2C716&ssl=1)
[astro-ph.SR] Stellar elemental abundances provide important constraints on the chemical environments from which planets form. M and late-K dwarfs are prime targets for the characterization of small exoplanets, yet their […]
astro-ph.SR
![Panel (a): HR diagram of the OC members with detections. The blue solid line is the fitting results of MS. green dashed lines represent the upper and lower bounds of the MS fitted with a ±0.5 offset, and the red dashed line is the same sequence shifted upwards by 2. The color bars represent the stellar ages. Panel (b): HR diagram of the field stars with detections. Panel (c): The Galactic distribution of the selected sources from the detected OC members. Panel (d): The Galactic distribution of the selected sources from the detected field stars. -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Evolution-of.png?resize=1200%2C720&ssl=1)
Posted inHabitable Zones
Evolution of Stellar Activity and Habitable Zone (EATEN): III. X-ray Activity of Dwarfs in Open Clusters and Field Stars
[astro-ph.SR] Stellar X-ray emission serves as a direct diagnostic of coronal activity, which is fundamentally linked to coronal heating processes. It also strongly influences the atmospheres and long-term habitability of […]
![Cumulative oxygen loss for planets at the habitable zone of each sample star over 1 Gyr, assuming constant stellar XUV flux at the HZ and no replenishment of oxygen. The curves are calculated using the energy-limited O2 loss prescription from V. S. Airapetian et al. 2017. Colored lines show individual stars, with solid segments representing the earliest ages (for stars with age ranges) and dashed segments extending beyond the minimum age. The black solid line shows the solar reference. Horizontal lines indicate the present-day Earth atmospheric O2 content (∼0.2 bars; dotted) and the total mass of Earth’s oceans (∼240 bars; dashed), providing reference levels for planetary habitability. -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Panchromatic.png?resize=1200%2C720&ssl=1)
Posted inHabitable Zones
Panchromatic Spectra of Nearby Low-mass and Sun-like Stars with Directly Imageable Habitable Zones
[astro-ph.SR] Characterizing the high-energy radiation environments of stars plays a critical role in determining which systems’ planets are capable of retaining atmospheres and sustaining habitable conditions.
![Keck/NIRSPEC M -band spectrum of TRAPPIST-1 (black) with best-fit model (red). Top: echelle order 16 (λ ≈ 4.63–4.73 µm). Bottom: order 15 (λ ≈ 4.93–5.04 µm). Residuals (data minus model) are shown beneath each panel. Gray shading indicates the relative telluric transmission (dimensionless, 0–1). Masked pixels are omitted from the retrieval. -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-Isotopic.png?resize=1200%2C721&ssl=1)
Posted inTRAPPIST-1
The Isotopic And Elemental Abundances of Planet-Host Star TRAPPIST-1
[astro-ph.SR]. Elemental and isotopic abundances are key tracers of planet formation, stellar evolution, and Galactic chemical evolution. Very low-mass stars are particularly interesting in this regard, because unlike more massive […]
![Chemical abundance distributions of the Sample II planet-candidate host stars in the [Fe/H]–[Mg/Fe] plane.](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/A-chemo.png?resize=1200%2C715&ssl=1)
Posted inStellar Cartography
A Chemo-dynamical Search For Planet-candidate Hosts Of Possible Extragalactic Origin
[astro-ph.SR] To date, all known exoplanetary systems have been identified around stars currently residing in the Milky Way, whereas planets formed in external galaxies remain largely unexplored. Such systems would […]
![The top panel shows comparisons of the observed spectrum of JADES-GS-BD-11 (black with grey 1σ error bars) and the median retrieved spectrum for both the PH3 and non-PH3 petitRADTRANS (red and green, respectively, with 1σ central credible intervals shaded around the median). The bottom panel shows the difference between the retrieved and observed spectra, divided by the observed uncertainty. The two retrieved median spectra are generally within 1σ of each other everywhere except at 4.3 µm (the Q-branch of the PH3 feature).-- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/JWSTNIRSpec.png?resize=1200%2C717&ssl=1)
Posted inBrown Dwarfs
JWST/NIRSpec Spectra for Three Ultracool Brown Dwarfs Detected in Extragalactic Surveys: Further Evidence for Phosphine Absorption
[astro-ph.SR] We present JWST NIRSpec prism spectra for three ultracool brown dwarfs discovered in extragalactic survey data, two from the JWST Advanced Deep Extragalactic Survey (JADES), and one from Public […]
Posted inSpace Weather & Heliophysics
Intense but Harmless: Exo-Space Weather Around an M Dwarf with a Single-Hemisphere Dynamo
[astro-ph.SR] M dwarfs are among the most promising host stars in the search for habitable exoplanets. However, their active atmospheres drive intense magnetic activity, including energetic flares and possibly coronal […]
![TiO absorption variation during 8 years on surface of proxima centauri. Vertical lines depicts regions were used to measure B index. -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Titanium-Oxide.png?resize=1200%2C715&ssl=1)
Posted inProxima Centauri
Titanium Oxide Absorption as a Proxy to Detect Long term Variation and Activity Cycle in Proxima Centauri
[astro-ph.SR] Stellar activity cycles on magnetically active stars can be estimated by molecular absorption bands.
![Chemical structure of the aromatic nitriles cyanobenzene, d5-cyanobenzene, 1,2-dicyanobenzene, 1,3- dicyanobenzene and 1,4-dicyanobenzene -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Infrared.png?resize=1200%2C714&ssl=1)
Posted inAstrochemistry
Infrared Spectroscopy and Photochemistry of Aromatic Nitriles in Para-Hydrogen Matrices
[astro-ph.SR] Motivated by recent detections of several aromatic nitriles in Taurus Molecular Cloud-1, we report laboratory and theoretical investigations of the vibrational spectroscopy and photochemistry of singly and doubly cyano-substituted […]
Posted inAstrochemistry
An Interstellar Energetic And Non-aqueous Pathway To Peptide Formation
[astro-ph.SR] The origin of the molecular building blocks of life is a central question in science. A few α-amino acids such as glycine, the simplest proteinogenic amino acid, have been […]