Detectability of biosignatures on LHS 1140 b

Abstract

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 and is an excellent candidate for detecting atmospheric features. In this study, we investigate how the instellation and planetary parameters influence the atmospheric climate, chemistry, and spectral appearance of LHS 1140 b. We study the detectability of selected molecules, in particular potential biosignatures, with the upcoming James Webb Space Telescope (JWST) and Extremely Large Telescope (ELT). In a first step we use the coupled climate-chemistry model, 1D-TERRA, to simulate a range of assumed atmospheric chemical compositions dominated by H${}_2$ and CO${}_2$. Further, we vary the concentrations of CH${}_4$ by several orders of magnitude. In a second step we calculate transmission spectra of the simulated atmospheres and compare them to recent transit observations. Finally, we determine the observation time required to detect spectral bands with low resolution spectroscopy using JWST and the cross-correlation technique using ELT. In H${}_2$-dominated and CH${}_4$-rich atmospheres O${}_2$ has strong chemical sinks, leading to low concentrations of O${}_2$ and O${}_3$. The potential biosignatures NH${}_3$, PH${}_3$, CH${}_3$Cl and N${}_2$O are less sensitive to the concentration of H${}_2$, CO${}_2$ and CH${}_4$ in the atmosphere. In the simulated H${}_2$-dominated atmosphere the detection of these gases might be feasible within 20 to 100 observation hours with ELT or JWST, when assuming weak extinction by hazes. If further observations of LHS 1140 b suggest a thin, clear, hydrogen-dominated atmosphere, the planet would be one of the best known targets to detect biosignature gases in the atmosphere of a habitable-zone rocky exoplanet with upcoming telescopes.

arXiv comment18 pages, 11 figures

References in corpus (89)

• Gaia Data Release 2. Summary of the contents and survey properties
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b
• Kepler planets: a tale of evaporation
• The evaporation valley in the Kepler planets
• An asteroseismic view of the radius valley: stripped cores, not born rocky
• Core-powered mass loss and the radius distribution of small exoplanets
• Sculpting the Valley in the Radius Distribution of Small Exoplanets as a by-product of Planet Formation: The Core-Powered Mass-Loss Mechanism
• The MUSCLES Treasury Survey I: Motivation and Overview
• A ground-based transmission spectrum of the super-Earth exoplanet GJ1214b
• A temperate rocky super-Earth transiting a nearby cool star
• Water Vapor and Clouds on the Habitable-Zone Sub-Neptune Exoplanet K2-18b
• Hydrogen Greenhouse Planets Beyond the Habitable Zone
• Super-Earth Atmospheres: Self-Consistent Gas Accretion and Retention
• Atmospheric Chemistry in Giant Planets, Brown Dwarfs, and Low-Mass Dwarf Stars II. Sulfur and Phosphorus
• Photochemistry in Terrestrial Exoplanet Atmospheres I: Photochemistry Model and Benchmark Cases
• Retrieving Temperatures and Abundances of Exoplanet Atmospheres with High-Resolution Cross-Correlation Spectroscopy
• Finding extraterrestrial life using ground-based high-resolution spectroscopy
• Make Super-Earths, Not Jupiters: Accreting Nebular Gas onto Solid Cores at 0.1 AU and Beyond
• Impact of Space Weather on Climate and Habitability of Terrestrial Type Exoplanets
• Observing the Atmospheres of Known Temperate Earth-sized Planets with JWST
• The MUSCLES Treasury Survey III: X-ray to Infrared Spectra of 11 M and K Stars Hosting Planets
• The Detectability and Characterization of the TRAPPIST-1 Exoplanet Atmospheres with JWST
• Abiotic Ozone and Oxygen in Atmospheres Similar to Prebiotic Earth
• Abiotic O${}_2$ Levels on Planets around F, G, K, and M Stars: Possible False Positives for Life?
• High Stellar FUV/NUV Ratio and Oxygen Contents in the Atmospheres of Potentially Habitable Planets
• Effect of UV Radiation on the Spectral Fingerprints of Earth-like Planets Orbiting M dwarfs
• Observational evidence for a metal rich atmosphere on the super-Earth GJ1214b
• The Atmospheric Chemistry of GJ 1214b: Photochemistry and Clouds
• Photochemistry in Terrestrial Exoplanet Atmospheres III: Photochemistry and Thermochemistry in Thick Atmospheres on Super Earths and Mini Neptunes
• Abiotic formation of O2 and O3 in high-CO2 terrestrial atmospheres
• Feasibility Studies for the Detection of $O_2$ in an Earth-like Exoplanet
• Biosignature Gases in H2-Dominated Atmospheres on Rocky Exoplanets
• How formation time-scales affect the period dependence of the transition between rocky super-Earths and gaseous sub-Neptunes and implications for ${\eta }_{\oplus }$
• Thermochemistry and Photochemistry in Cooler Hydrogen Dominated Extrasolar Planets: The Case of GJ436b
• Pale Orange Dots: The Impact of Organic Haze on the Habitability and Detectability of Earthlike Exoplanets
• Haze Production in the Atmospheres of super-Earths and mini-Neptunes: Insights from the Lab
• The Response of Atmospheric Chemistry on Earthlike Planets around F, G and K Stars to Small Variations in Orbital Distance
• The Mid-Infrared Instrument for the James Webb Space Telescope: IV. The Low Resolution Spectrometer
• Hydrogen dimers in giant-planet infrared spectra
• Detectability of atmospheric features of Earth-like planets in the habitable zone around M dwarfs
• Outgassing on stagnant-lid super-Earths
• A Biomass-based Model to Estimate the Plausibility of Exoplanet Biosignature Gases
• A Volcanic Hydrogen Habitable Zone
• Titan solar occultation observations reveal transit spectra of a hazy world
• Scaling K2. I. Revised Parameters for 222,088 K2 Stars and a K2 Planet Radius Valley at 1.9 $R_{\oplus }$
• Detection of Propene in Titan's Stratosphere
• A second terrestrial planet orbiting the nearby M dwarf LHS 1140
• Strategies for Constraining the Atmospheres of Temperate Terrestrial Planets with JWST
• Dust Ablation on the Giant Planets: Consequences for Stratospheric Photochemistry
• Planetary system LHS 1140 revisited with ESPRESSO and TESS
• 1D atmospheric study of the temperate sub-Neptune K2-18b
• Titan's atmosphere as observed by Cassini/VIMS solar occultations: CH${}_4$, CO and evidence for C${}_2$H${}_6$ absorption
• Photochemistry of Anoxic Abiotic Habitable Planet Atmospheres: Impact of New H${}_2$O Cross-Sections
• Neptune's Atmospheric Composition from AKARI Infrared Spectroscopy
• Photochemical Haze Formation in the Atmospheres of super-Earths and mini-Neptunes
• No snowball on habitable tidally locked planets
• Hubble WFC3 Spectroscopy of the Habitable-zone Super-Earth LHS 1140 b
• Constraining the Origins of Neptune's Carbon Monoxide Abundance with CARMA Millimeter-wave Observations
• Sensitivity of Biosignatures on Earth-like Planets orbiting in the Habitable Zone of Cool M-Dwarf Stars to varying Stellar UV Radiation and Surface Biomass Emissions
• Seasonal stratospheric photochemistry on Uranus and Neptune
• GJ 1214b revised. Improved trigonometric parallax, stellar parameters, orbital solution, and bulk properties for the super-Earth GJ 1214b
• Habitability and Spectroscopic Observability of Warm M-dwarf Exoplanets Evaluated with a 3D Chemistry-Climate Model
• Effect of Pressure Broadening on Molecular Absorption Cross Sections in Exoplanetary Atmospheres
• Re-analysis of the 267-GHz ALMA observations of Venus: No statistically significant detection of phosphine
• Isotopic Ratios of Carbon and Oxygen in Titan's CO using ALMA
• Photochemical hazes in sub-Neptunian atmospheres with focus on GJ 1214 b
• A stringent upper limit of the PH${}_3$ abundance at the cloud top of Venus
• EELT-HIRES the high-resolution spectrograph for the E-ELT
• A Methane Extension to the Classical Habitable Zone
• Outstanding Challenges of Exoplanet Atmospheric Retrievals
• Latitudinal variation in the abundance of methane (CH4) above the clouds in Neptune's atmosphere from VLT/MUSE Narrow Field Mode Observations
• Distinguishing between wet and dry atmospheres of TRAPPIST-1 e and f
• The statistical reliability of 267 GHz JCMT observations of Venus: No significant evidence for phosphine absorption
• O2- and CO-Rich Atmospheres for Potentially Habitable Environments on TRAPPIST-1 Planets
• New Insights into Cosmic Ray induced Biosignature Chemistry in Earth-like Atmospheres
• Consistently Simulating a Wide Range of Atmospheric Scenarios for K2-18b with a Flexible Radiative Transfer Module
• Rethinking CO Antibiosignatures in the Search for Life Beyond the Solar System
• No Snowball on Habitable Tidally Locked Planets with a Dynamic Ocean
• Testing the Detectability of Extraterrestrial ${\mathrm{O}}_2$ with the ELTs using Real Data with Real Noise
• Spectroscopic characterization of the atmospheres of potentially habitable planets: GL 581 d as a model case study
• Sulfate Aerosol Hazes and SO2 Gas as Constraints on Rocky Exoplanets' Surface Liquid Water
• Transmission Spectroscopy with the ACE-FTS Infrared Spectral Atlas of Earth: A Model Validation and Feasibility Study
• Simultaneous Optical Transmission Spectroscopy of a Terrestrial, Habitable-Zone Exoplanet with Two Ground-Based Multi-Object Spectrographs
• 1D photochemical model of the ionosphere and the stratosphere of Neptune
• Effect of O3 on the atmospheric temperature structure of early Mars
• Limitation of atmospheric composition by combustion-explosion in exoplanetary atmospheres
• The high-energy radiation environment of the habitable-zone super-Earth LHS 1140b

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• Prebiosignature Molecules Can Be Detected in Temperate Exoplanet Atmospheres with JWST
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• Polarized Signatures of a Habitable World: Comparing Models of an Exoplanet Earth with Visible and Near-infrared Earthshine Spectra
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