A recent observation of the exoplanet K2-18b sparked interest among scientists – large amounts of carbon dioxide and methane were detected in an H2-rich background atmosphere.
GJ 436
Posted inAstrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release, Water/Hycean Worlds & Oceanography
Signs Of Alien Life May Be Hiding In These Gases
Scientists have identified a promising new way to detect life on faraway planets, hinging on worlds that look nothing like Earth and gases rarely considered in the search for extraterrestrials.
Posted inAtmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography
Examining the Potential for Methyl Halide Accumulation and Detectability in Possible Hycean-Type Atmospheres
Some sub-Neptune planets may host habitable conditions; for example “Hycean” worlds with H2 envelopes over liquid water oceans can maintain potentially hospitable pressures and temperatures at their surface.
Posted inAstrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Lava / magma ocean / Volcanic Worlds, Status Report, Venus
Venus as an Exoplanet: I. An Initial Exploration of the 3-D Energy Balance for a CO2 Exoplanetary Atmosphere Around an M-Dwarf Star
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 […]
![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)
Posted inAstrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, Stellar Cartography, Water/Hycean Worlds & Oceanography
Stellar Characterization and Chemical Abundances of Exoplanet Hosting M dwarfs from APOGEE Spectra: Future JWST Targets
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 […]
Posted inAtmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography
Biogenic Sulfur Gases As Biosignatures On Temperate Sub-Neptune Waterworlds
Theoretical predictions and observational data indicate a class of sub-Neptune exoplanets may have water-rich interiors covered by hydrogen-dominated atmospheres. Provided suitable climate conditions, such planets could host surface liquid oceans.
Posted inExoplanets, -moons, -comets, Extinction events, Habitable Zones, Space Weather & Heliophysics, Status Report
The Space Weather Around The Exoplanet GJ 436 b. II. Stellar Wind-exoplanet Interactions
The M dwarf star GJ 436 hosts a warm-Neptune that is losing substantial amount of atmosphere, which is then shaped by the interactions with the wind of the host star. […]
Posted inAstronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Space Weather & Heliophysics, Status Report
The Space Weather Around The Exoplanet GJ 436b
The space environment in which planets are embedded depends mainly on the host star and impacts the evolution of the planetary atmosphere. The quiet M dwarf GJ 436 hosts a […]