![Distributions of planetary mass, mass of the host star and semi-major axis of all confirmed exoplanets listed at exoplanet.eu. The planets are color-coded according to method used for their discovery. The dashed gray line marks the deuterium-burning mass limit of 13 MJup. [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Characterization-1.png?resize=1200%2C710&ssl=1)
[astro-ph.EP] Astrometry is the oldest method used to search for extrasolar planets. This technique provides key information about a planetary system, like the true mass of planets and its three-dimensional […]
Stellar Cartography
![Top-down, to-scale view of the TOI-789 architecture. The four planetary orbits are drawn around the M3 host (center); symbol size scales with planetary radius and symbol color with equilibrium temperature (color bar). The candidate .04 is drawn with a dashed outline. Shaded annular bands mark, from the inside out, the Venus zone (Kane et al. 2014), the temperate region defined by Teq = 273– 400 K, and the inner edge of the Kopparapu et al. (2014) habitable zone. The four planets form a sequence of decreasing insolation that crosses the Venus zone, with the candidate .04 near the inner edge of the habitable zone.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Characterization.png?resize=1200%2C719&ssl=1)
Posted inExoplanets, -moons, -comets
Characterization of the Compact Multi-planet System TOI-789: Validation of Three Terrestrial Planets, Dynamical Characterization, and Detection of a Fourth Temperate Candidate
[astro-ph.EP] We present the validation and dynamical characterization of TOI-789 (TIC 300710077), a compact multi-planet system around an M3 dwarf at 43 pc.
![Radius valley plot showing the sub-populations of super-Earths and sub-Neptunes as circles and triangles, respectively. The black line and grey shaded region denote an average radius valley (Ho & Van Eylen 2023) for the population and its 1𝜎 uncertainty region, respectively. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/No-Statistically-.png?resize=1200%2C720&ssl=1)
Posted inStellar Cartography
No Statistically Significant Evidence For A Correlation Between Stellar And planetary Composition
[astro-ph.EP] The chemical compositions of planets and their hosts stars are intrinsically linked, having formed from the same protostellar material.
![Radial velocity timeseries of K2-3 used in the analysis. Here the second dimension for the multi-dimensional quasi-periodic gaussian process kernes used the D2V activity indicator to disentangle the stellar activity from the Keplerian signals. The Keplerian models for all three planets are assumed to be circular orbits for this figure (Model 1 in Table C.3). The various instruments used in the analysis are colour coded. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Uncovering.png?resize=1200%2C719&ssl=1)
Posted inExoplanets, -moons, -comets
Uncovering Temperate Worlds: An Updated Look At The K2-3 System With ESPRESSO
[astro-ph.EP] The K2-3 system is one of the most unique planetary systems as it features three transiting sub-Neptunes in decreasing order of radii, spanning the radius valley.
Posted inExoplanets, -moons, -comets
Youngest Exoplanet Yet Discovered Found Hiding in Keck Observatory Data
[W.M.Keck Observatory] Astronomers have confirmed the youngest exoplanet detected so far, offering a rare glimpse into the earliest stages of planetary formation. The planet, known as Elias 2-24 b, is […]
![Disk properties [Ri,Rco,Rdust] and exoplanet semimajor axis values are plotted in units of the PMS host stellar radius as a function of host star mass. The plot shows planets are less common inside the disk corotation radius suggesting that planetary inward migration is frequently halted in the vicinity of the corotation radius. Some planets have semimajor axis values < Rdust the dust sublimation radius, implying that planet migration must have occurred to populate the semimajor axis < Rdust region. Ri & Rco (gray diamonds and red squares respectively) are from the Pittman et al. (2025b) survey. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Exoplanet-System.png?resize=1200%2C719&ssl=1)
Posted inExoplanets, -moons, -comets
Exoplanet System Architecture: Sculpting the Inner Regions
[astro-ph.EP] In this study, we seek to improve our understanding of the competing roles of disk-driven and planet-planet dynamical migration in sculpting planetary system architecture in the inner ≲1.5 au […]
Posted inStellar Cartography
Fingerprints Inside Our Sun Could Reveal If It Once Swallowed A Planet
[Royal Astronomical Society] It is thought the Sun may have engulfed a super-Earth-sized planet early in its history.
![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 […]
Posted inTRAPPIST-1
Radial Velocity Detection Of The TRAPPIST-1 Planetary System With SPIRou And NIRPS
[astro-ph.EP]. The TRAPPIST-1 system is well-known for its seven transiting Earth-sized exoplanets. It has been extensively studied and characterized, notably with transit timing variations (TTVs) to precisely measure the mass […]
![The black line shows the empirical high-S/N template spectrum of Proxima Centauri (left) and Barnard’s Star (right). In the top panel, the green curve shows the median spectrum obtained by taking the median flux at each wavelength across the full grid of PHOENIX M-dwarf spectra, while the shaded region denotes the corresponding 1σ envelope. Comparing this range of model spectra with the empirical M-dwarf spectra demonstrates that the PHOENIX models do not adequately reproduce the observed spectra. The middle and bottom panels show either empirical templates or postellar spectral samples constructed from synthetic SPIRou observations of the respective stars at different S/N regimes. For the postellar spectra, the 1σ, 2σ, and 3σ intervals are shown, highlighting the uncertainties recovered on individual spectral feature. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/POSTELLAR.png?resize=1200%2C721&ssl=1)
Posted inExoplanets, -moons, -comets
POSTELLAR: Posterior Stellar Spectrum Sampling – An Alternative to Approximate Stellar Spectra for Exoplanetary Analysis
[astro-ph.EP] We present a novel approach to perform posterior sampling of the underlying stellar spectrum in high-resolution spectroscopic observations.