Super-Earths orbiting M-dwarf stars may be the most common habitable planets in the Universe. However, their habitability is threatened by intense irradiation from their host stars, which drives the escape […]
Recently, cyanobacteria have gained attention in space exploration to support long-term crewed missions via Bioregenerative Life Support Systems. In this frame, cyanobacteria would provide biomass and profitable biomolecules through oxygenic […]
![ChM diagram of M dwarfs in 47 Tucanae from JWS T-HS T photometry (grey dots). Spectroscopic targets observed with NIRSpec@JWS T are represented with filled coloured circles. Targets with no available mF322W2 from NIRCam@JWS T are plotted with ∆C F606W,F814W,F322W2=0.00 as empty circles. Different colors have been used for stars associated with different stellar populations on the ChM, specifically: first population (1P) stars are colored in red, second population ones have been colored in orange (2Pa), cyan (2Pb) and blue (2Pe). The [O/Fe] abundance vs. the ∆F606W,F814W and ∆C F606W,F814W,F322W2 values is shown in the upper and right panels, respectively. For each population, we plot the average values and the associated error. -- astro-ph.GA](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/06/A-JWST-project-on-47-Tucanae.png?resize=1200%2C720&ssl=1)
We present the first spectroscopic estimates of the chemical abundance of M dwarf stars in a globular cluster (GC), namely 47 Tucanae. By exploiting NIRSpec on board the James Webb […]
Planets orbiting binary systems are relatively unexplored compared to those around single stars. Detections of circumbinary planets and planetary systems offer a first detailed view into our understanding of circumbinary […]
The chemical evolution of an exoplanetary Venus-like atmosphere is dependent upon the ultraviolet to near ultraviolet (FUV-NUV) radiation ratio from the parent star, the balance between CO2 photolysis and recombination […]
![Comparison of SPECULOOS-3 b with other rocky exoplanets. a) Sizes of host stars and incident stellar flux of known sub-Neptune-sized exoplanets. The size of the symbols scales linearly with the radius of the planet. The background is colour-coded according to stellar size (in units of the Sun’s size), with the ultra-cool dwarf regime shown in orange. The positions of the Solar System terrestrial planets are shown for reference. One can see on this Figure that SPECULOOS-3 b extends the unique planet sample of TRAPPIST-1 to a larger stellar flux. b) SPECULOOS-3 b in the context of other known transiting terrestrial exoplanets (Rp < 1.6R⊕) that are cool enough (Teq < 880 K [80]) to have a dayside made of solid rock (in contrast to hotter magma worlds with molten surfaces). The planets are shown as a function of their radius and their Emission Spectroscopy Metric [62]. They are color-coded as a function of their equilibrium temperature. The shaded green area highlights planetary radii most similar to Earth’s (0.9–1.1 R⊕). The dashed horizontal line represents the threshold of ESM=7.5 recommended by ref. [62] to identify the top targets for emission spectroscopy with JWST. SPECULOOS-3 b is one of the smallest planets amenable to emission spectroscopy with MIRI/LRS. Data from https://exoplanetarchive.ipac.caltech.edu (16th of October 2023). -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/06/Detection-Of-An-Earth-sized-Exoplanet.png?resize=1200%2C720&ssl=1)
Located at the bottom of the main sequence, ultracool dwarf stars are widespread in the solar neighbourhood. Nevertheless, their extremely low luminosity has left their planetary population largely unexplored, and […]
![The [Fe/H] versus C/O distribution for this work sample, as well as other M dwarfs studied by Souto et al. (2017), Souto et al. (2018), Souto et al. (2020). The orange circles represent the results for the four JWST targets studied here; Results for M dwarfs from our previous studies (all based on the same methodology as here) are also shown: orange triangles are M dwarfs with exoplanets detected, while the gray squares are M dwarfs without exoplanets detected so far. We also present results for FGK dwarfs from Nissen (2013) (green triangles; all with detected exoplanets), Teske et al. (2014) with (light blue diamonds) detected exoplanets, and Delgado Mena et al. (2021) with (pink circles), and without detected exoplanets (yellow cross). Additionally, four curves represent the linear regressions of the [Fe/H] vs. C/O distribution for M dwarfs with planet detected (solid orange line), M dwarfs without planet detected (solid gray line), FGK dwarfs with detected planets (dashed orange line), and FGK dwarfs without detected planets (dashed gray line). -- astro-ph.SR](https://i0.wp.com/astrobiology.com/wp-content/uploads/2024/06/Stellar-Characterization-and.png?resize=1200%2C719&ssl=1)
Exoplanets hosting M dwarfs are the best targets to characterize Earth-like or super-Earth planetary atmospheres with the James Webb Space Telescope (JWST). We determine detailed stellar parameters (Teff, logg, and […]
The habitability of exoplanets hosted by M-dwarf stars dramatically depends on their space weather. We present 3D magneto-hydrodynamic simulations to characterise the magneto-plasma environment and thus the habitability of the […]
We present an updated characterization of the TOI-1685 planetary system, which consists of a Pb = 0.69 day USP super-Earth planet orbiting a nearby (d = 37.6 pc) M2.5V star […]
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observations.
