SIMBAD references

Due to its Earth-like minimum mass of 1.27 M_E and its close proximity to our solar system, Proxima Centauri b is one of the most interesting exoplanets for habitability studies. Its host star, Proxima Centauri, is however a strongly flaring star, which is expected to provide a very hostile environment for potentially habitable planets. We perform a habitability study of Proxima Centauri b assuming an Earth-like atmosphere under high stellar particle bombardment, with a focus on spectral transmission features. We employ our extensive model suite calculating energy spectra of stellar particles, their journey through the planetary magnetosphere, ionosphere, and atmosphere, ultimately providing planetary climate and spectral characteristics, as outlined in Herbst et al. Our results suggest that together with the incident stellar energy flux, high particle influxes can lead to efficient heating of the planet well into temperate climates, by limiting CH₄ amounts, which would otherwise run into antigreenhouse for such planets around M stars. We identify some key spectral features relevant for future spectral observations: First, NO₂ becomes the major absorber in the visible, which greatly impacts the Rayleigh slope. Second, H₂O features can be masked by CH₄ (near-infrared) and CO₂ (mid- to far-infrared), making them nondetectable in transmission. Third, O₃ is destroyed and instead HNO₃ features become clearly visible in the mid- to far-infrared. Lastly, assuming a few percent of CO₂ in the atmosphere, CO₂ absorption at 5.3 µm becomes significant (for flare and nonflare cases), strongly overlapping with a flare related NO feature in Earth's atmosphere.