![Transmission spectra of TRAPPIST-1 c from the four JWST/NIRSpec PRISM epochs (4-pixel bins, 0.8–5.0 𝜇m), offset vertically by 200 ppm per epoch for clarity and colour-coded by date, with the inverse-variance-weighted mean spectrum (black, plotted at its true depth). Grey bands mark the stellar H2O features near 1.4 and 1.85 𝜇m. The dotted line marks 2.0 𝜇m, the boundary of the region where the contamination is strongest (Section 3). The 2023 November 8 visit contains a flare during transit and the 2024 July 9 visit shows activity outside transit (Section 2.5). -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Detecting.png?resize=1200%2C716&ssl=1)
[astro-ph.EP] Transmission spectroscopy of rocky exoplanets orbiting late M dwarfs is limited by stellar contamination rather than photon noise.
TRAPPIST-1
![Atmospheric and water loss of an Earth-like planet for three stellar systems: (e,f) M-dwarf (TRAPPIST-1) central habitable zone. The mass losses shown in a,b,c and d are after 6 Gyr of system integration. -- Full chart below [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Simulated-Effects.png?resize=1200%2C718&ssl=1)
Posted inExoplanets, -moons, -comets
Simulated Effects of Radioactive Elements on Magnetic Evolution and Atmospheric Mass Loss of Earth-like Planets
[astro-ph.EP] Thousands of exoplanets have been discovered in recent decades, yet Earth remains the only known world with life.
Posted inSETI & Technosignatures
Is A Nearby Advanced Alien Civilization Out There Waiting To Pounce On Earth? Unlikely, Says New Study
[Northern Arizona University] Science fiction suggests that life on other planets, if it exists, is likely far more advanced than life on Earth.
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 […]
![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 […]
![Differences in the TLS effect for the TRAPPIST-1 planets for our minimal two-zone model. The left panel shows a representative diagram of the stellar surface with increased spottedness in the polar regions. Lines are drawn to represent the center of the transit chord for each of the TRAPPIST-1 planets. As a representative example, the width of planet b’s transit chord is shaded in blue. In the right panel, the relative transit depth is shown assuming only stellar heterogeneity made up of cooler regions (upper) and hotter regions (lower) with no contribution from a planetary atmosphere over the wavelength range relevant to JWST NIRSpec/PRISM. The higher impact parameter planets (f, g, and h) are less impacted by the TLS effect than the lower impact parameter planets given our choice of zonal boundary. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Leveraging-Impact.png?resize=1200%2C717&ssl=1)
Posted inTRAPPIST-1
Leveraging Impact Parameter to Mitigate the Transit Light Source Effect: Early Insights from TRAPPIST-1
[astro-ph.EP] Stellar activity complicates exoplanet transmission spectra, particularly for smaller planets around M dwarfs with JWST.
![Simulations of the external planets’ (d to h) contributions at the times of JWST observations (represented in color over the bare rocks total curve). Relative fluxes were simulated using the SPHINX spectrum at 12.8 microns. The contributions of each planet are shown in colored dotted lines and the case of all planets with thick atmospheres in dashed grey. The total phase curves correspond to the total contribution of the external planets. Eclipses are displayed but not transits. Visit 1 of GTO 1279 is not displayed as the observational strategy from this visit was different from the others and less precise (Ducrot et al. 2024) -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Looking.png?resize=1200%2C717&ssl=1)
Posted inTRAPPIST-1
Looking For TRAPPIST-1 External Planets’ Emission In JWST Archival Data
[astro-ph.EP] The TRAPPIST-1 system has been thoroughly observed with JWST. Unfortunately, stellar contamination issues strongly limit the interpretation of transit observations.
Posted inTRAPPIST-1
Atmospheric Reconnaissance of TRAPPIST-1 f with JWST NIRISS SOSS: No Evidence for the Transit Light Source Effect
[astro-ph.EP] In just over three years of operation, JWST has observed all seven planets of the TRAPPIST-1 system. The two innermost planets were found to have little to no atmosphere, […]
![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 […]
Posted inHabitable Zones
Quantifying Detection Bias And Recovering Habitable Zone Occurrence Rates In The NASA Exoplanet Archive
[Astronomy and Computing] Transit surveys tend to underestimate how often habitable zone (HZ) planets appear. The core reason is geometric: the chance that an Earth-like planet transits a sun-like star […]