Detectability of biosignatures on LHS 1140 b

Context. Terrestrial extrasolar planets around low-mass stars are prime targets when searching for atmospheric biosignatures with current and near-future telescopes. The habitable-zone super-Earth LHS 1140 b could hold a hydrogen-dominated atmosphere, is an excellent candidate detecting features. Aims. In this study we investigate how the instellation planetary parameters influence climate, chemistry, spectral appearance of b. We detectability selected molecules, in particular potential biosignatures, upcoming James Webb Space Telescope (JWST) Extremely Large (ELT). Methods. first step used coupled climate–chemistry model 1D-TERRA to simulate range assumed chemical compositions dominated by molecular hydrogen (H 2 ) carbon dioxide (CO ). addition, varied concentrations methane (CH 4 several orders magnitude. second calculated transmission spectra simulated atmospheres compared them recent transit observations. Finally, determined observation time required detect bands low-resolution spectroscopy using JWST, cross-correlation technique ELT. Results. H -dominated CH -rich oxygen (O has strong sinks, leading low O ozone 3 ammonia (NH ), phosphine (PH chloromethane Cl), nitrous oxide (N O) less sensitive concentration , CO atmosphere. atmosphere detection these gases might be feasible within 20 100 hours ELT or JWST assuming weak extinction hazes. Conclusions. If further observations suggest thin, clear, planet would one best known biosignature rocky exoplanet