![Benchmark test between chemcat (dashed black lines) and GGchem (solid colored lines) for a network of neutral species at 1 bar and temperatures from 100–6000 K (only selected species are shown). Both codes produced results typically consistent within 0.1 dex, with noticeable differences resulting from missing thermochemical data or at the lowest temperatures T ≲ 200 K. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Pyrat-Bay.png?resize=1200%2C713&ssl=1)
[astro-ph.EP] This article presents a major update to the open-source Pyrat Bay modeling framework (version 2.0), tailored for the characterization of exoplanet atmospheres with the observational capabilities of current facilities, […]
astro-ph.EP
![Illustration of the VHS 1256 b data used in this study. (Top) Full ERS #1386 program (V2) spectrum of VHS 1256 b with overlapping wavelengths between orders shown in grey. With 12 spectral orders populating the NIRSpec and MIRI data combination we have 11 overlaps present across the global spectrum. (Middle) NIRSpec data at its native resolution and the binned spectrum used in our retrieval analysis. (Bottom) MIRI data at its native resolution and the binned spectrum used in our retrieval analysis. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-JWST.png?resize=1200%2C719&ssl=1)
Posted inExoplanets, -moons, -comets
The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems VIII: Patchy Forsterite and Enstatite Clouds in the Atmosphere of VHS 1256 b.
[astro-ph.EP] JWST defines a new era for the data-driven approach of retrieval modelling, which has become a cornerstone tool for the statistical inference of exoplanetary and brown dwarf properties.
![Illustration of the TRAPPIST-1 system and the most recent JWST constraints on planetary atmospheres. Planet size and distance roughly to scale. - [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/veiled.png?resize=1200%2C820&ssl=1)
Posted inTRAPPIST-1
Veiled in Starlight: Impacts of Stellar Contamination On Retrievals of TRAPPIST-1f’s Atmospheric Composition
[astro-ph.EP] The TRAPPIST-1 system offers seven terrestrial exoplanets with tight orbits and large radii ratios to the host star. If an atmosphere exists, transmission spectroscopy can be used to detect […]
![Inclination vs. semimajor axis for the NEOs. The main asteroid families that have been linked to ordinary chondrites are represented by gray squares. The ν6 secular resonance with Saturn and the 3:1 and 5:2 mean motion resonances with Jupiter are represented with dashed lines. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Size-Constraints.png?resize=1200%2C718&ssl=1)
Posted inAstrogeology
Size Constraints For The Pre-atmospheric Parent Bodies Of Ordinary Chondrites
[astro-ph.EP] The study of S-complex near-Earth objects (NEOs), the parent bodies of ordinary chondrites, has shown that they are dominated by asteroids with LL chondrite-like compositions. This is surprising because […]
![The mass-radius-period parameter spaces for short-period exoplanets. In (a), the radii and orbital periods of known planets are shown with systems coloured by the stellar effective temperature. The TASSIE II TOIs are highlighted as points with 3σ error bars for their radii. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-TASSIE-Program.png?resize=1200%2C719&ssl=1)
Posted inExoplanets, -moons, -comets
The TASSIE Program. II: Three Close-In Companions Orbiting Sun-Like Stars
[astro-ph.EP] We present three southern transiting giant planet candidates alerted by the Transiting Exoplanet Survey Satellite (TESS) mission and investigated at the University of Tasmania Greenhill Observatory (UTGO).
Posted inExoplanets, -moons, -comets
Exploration Of Exoplanet Atmospheres With The James Webb Space Telescope
[astro-ph.EP] The James Webb Space Telescope (JWST) is providing transformative characterization capabilities for the study of both transiting and directly imaged extrasolar planets. Observations deep into the infrared in the […]
Posted inJupiter
Joint Dynamical-geophysical Evidence For A Limit Cycle In The Galilean Moons
[astro-ph.EP] Io, Europa, and Ganymede orbit in the Laplace mean-motion resonance, where their orbital and thermochemical evolution are strongly coupled [1-5]. Forced eccentricities sustain tidal dissipation, powering Io’s volcanism and […]
Posted inExoplanets, -moons, -comets
JWST Transmission Spectroscopy Of TOI-3235 b: Challenges In Constraining Giant Planet Atmospheres Around M Dwarfs Amid Stellar Contamination
[astro-ph.EP] Giant planets orbiting low-mass M dwarfs challenge current planet formation theories, which predict that such planets are unlikely to form. Characterizing their atmospheres can provide key insight into their […]
Posted inExoplanets, -moons, -comets
Searching For Habitable Exoplanets With Relative Astrometry (SHERA). I. The Case For Searching For Planets In Binary Star Systems
[astro-ph.EP] Discovering Earth-like planets orbiting Sun-like stars was identified as a priority science goal of the Astronomy 2020 Decadal Survey.
![The band depths and centers of Callisto’s CO2 as measured at 4.25 µm for three viewing geometries. The trailing hemisphere and Asgard-centered data were previously published by Cartwright et al. (2024). The following geologic units are marked with symbols: Valhalla, ⋆ ; Asgard, ◦; Lofn/Heimdall, △. The sub-observer longitude of the observation is indicated in the panels. The projected angular size of Callisto varies slightly between each observation, so the spaxel scale is slightly different in each panel. The typical uncertainty in the band depth is ± 0.4%, while the band center is ±0.0006µm -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Callisto.png?resize=1200%2C709&ssl=1)
Posted inCallisto
Callisto From JWST: CO2-rich Terrain On The Leading Hemisphere And Global Patterns Of H2O Ice
[astro-ph.EP] We present maps of H2O, CO2, and a 4.57 um spectral feature across Callisto’s surface observed using the James Webb Space Telescope (JWST).