Atmospheric reconnaissance of the habitable-zone Earth-sized planets orbiting TRAPPIST-1

  title={Atmospheric reconnaissance of the habitable-zone Earth-sized planets orbiting TRAPPIST-1},
  author={Julien de Wit and Hannah R. Wakeford and Nikole K. Lewis and Laetitia Delrez and Micha{\"e}l Gillon and Frank Selsis and J{\'e}r{\'e}my Leconte and B-O. Demory and {\'E}meline Bolmont and Vincent Bourrier and Adam J. Burgasser and Simon L. Grimm and Emmanuel Jehin and Susan M. Lederer and James E. Owen and Vlada Stamenkovi{\'c} and Amaury H. M. J. Triaud},
  journal={Nature Astronomy},
Seven temperate Earth-sized exoplanets readily amenable for atmospheric studies transit the nearby ultracool dwarf star TRAPPIST-1 (refs 1,2). Their atmospheric regime is unknown and could range from extended primordial hydrogen-dominated to depleted atmospheres3–6. Hydrogen in particular is a powerful greenhouse gas that may prevent the habitability of inner planets while enabling the habitability of outer ones6–8. An atmosphere largely dominated by hydrogen, if cloud-free, should yield… 
Surface and Oceanic Habitability of Trappist-1 Planets under the Impact of Flares.
It is found that for non-oxygenic planets, UV-resistant life-forms would survive on the surface of planets f and g, and more fragile organisms (i.e., Escherichia coli) could be protected from the hazardous UV effects at ocean depths greater than 8 m.
Evolved Climates and Observational Discriminants for the TRAPPIST-1 Planetary System
The TRAPPIST-1 planetary system provides an unprecedented opportunity to study terrestrial exoplanet evolution with the James Webb Space Telescope (JWST) and ground-based observatories. Since M dwarf
Water vapour in the atmosphere of the habitable-zone eight-Earth-mass planet K2-18 b
In the past decade, observations from space and the ground have found water to be the most abundant molecular species, after hydrogen, in the atmospheres of hot, gaseous extrasolar planets1–5. Being
Detectability of Molecular Signatures on TRAPPIST-1e through Transmission Spectroscopy Simulated for Future Space-based Observatories
Discoveries of terrestrial, Earth-sized exoplanets that lie within the habitable zone (HZ) of their host stars continue to occur at increasing rates. Transit spectroscopy can potentially enable the
Searching for a dusty cometary belt around TRAPPIST-1 with ALMA
Low-mass stars might offer today the best opportunities to detect and characterize planetary systems, especially those harbouring close-in low-mass temperate planets. Among those stars, TRAPPIST-1
Predictions for Observable Atmospheres of Trappist-1 Planets from a Fully Coupled Atmosphere–Interior Evolution Model
The Trappist-1 planets provide a unique opportunity to test the current understanding of rocky planet evolution. The James Webb Space Telescope is expected to characterize the atmospheres of these
Clouds will Likely Prevent the Detection of Water Vapor in JWST Transmission Spectra of Terrestrial Exoplanets
We are on the verge of characterizing the atmospheres of terrestrial exoplanets in the habitable zones of M dwarf stars. Due to their large planet-to-star radius ratios and higher frequency of
Do the TRAPPIST-1 Planets Have Hydrogen-rich Atmospheres?
Recently, transmission spectroscopy in the atmospheres of the TRAPPIST-1 planets revealed flat and featureless absorption spectra, which rule out cloud-free, hydrogen-dominated atmospheres.
O2- and CO-rich Atmospheres for Potentially Habitable Environments on TRAPPIST-1 Planets
Small exoplanets of nearby M-dwarf stars present the possibility of finding and characterizing habitable worlds within the next decade. TRAPPIST-1, an ultracool M-dwarf star, was recently found to
Observing Isotopologue Bands in Terrestrial Exoplanet Atmospheres with the James Webb Space Telescope: Implications for Identifying Past Atmospheric and Ocean Loss
Terrestrial planets orbiting M dwarfs may soon be observed with the James Webb Space Telescope (JWST) to characterize their atmospheric composition and search for signs of habitability or life. These


A combined transmission spectrum of the Earth-sized exoplanets TRAPPIST-1 b and c
Observations of the combined transmission spectrum of the two inner planets during their simultaneous transits on 4 May 2016 rule out cloud-free hydrogen-dominated atmospheres for each planet at ≥10σ levels; TRAPPIST-1 b and c are therefore unlikely to have an extended gas envelope as they occupy a region of parameter space in which high-altitude cloud/haze formation is not expected to be significant for hydrogen- dominated atmospheres.
Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
The observations reveal that at least seven planets with sizes and masses similar to those of Earth revolve around TRAPPIST-1, and the six inner planets form a near-resonant chain, such that their orbital periods are near-ratios of small integers.
Observing the Atmospheres of Known Temperate Earth-sized Planets with JWST
Nine transiting Earth-sized planets have recently been discovered around nearby late-M dwarfs, including the TRAPPIST-1 planets and two planets discovered by the MEarth survey, GJ 1132b and LHS
Water loss from terrestrial planets orbiting ultracool dwarfs: implications for the planets of TRAPPIST-1
Ultracool dwarfs (UCD) encompass the population of extremely low mass stars (later than M6-type) and brown dwarfs. Because UCDs cool monotonically, their habitable zone (HZ) sweeps inward in time.
Temperate Earth-sized planets transiting a nearby ultracool dwarf star
Observations of three short-period Earth-sized planets transiting an ultracool dwarf star only 12 parsecs away suggest that 11 orbits remain possible for the third planet, the most likely resulting in irradiation significantly less than that received by Earth.
Temporal Evolution of the High-energy Irradiation and Water Content of TRAPPIST-1 Exoplanets
The ultracool dwarf star TRAPPIST-1 hosts seven Earth-size transiting planets, some of which could harbor liquid water on their surfaces. Ultraviolet observations are essential to measuring their
The inner edge of the habitable zone for synchronously rotating planets around low-mass stars using general circulation models
Terrestrial planets at the inner edge of the habitable zone (HZ) of late-K and M-dwarf stars are expected to be in synchronous rotation, as a consequence of strong tidal interactions with their host
Recent results from the Kepler mission indicate that super-Earths (planets with masses between 1–10 times that of the Earth) are the most common kind of planet around nearby Sun-like stars. These
Habitability of terrestrial-mass planets in the HZ of M Dwarfs – I. H/He-dominated atmospheres
The ubiquity of M dwarfs, combined with the relative ease of detecting terrestrial-mass planets around them, has made them prime targets for finding and characterising planets in the "Habitable Zone"
Extreme water loss and abiotic O2 buildup on planets throughout the habitable zones of M dwarfs.
In general, it is found that the initial phase of high luminosity may compromise the habitability of many terrestrial planets orbiting low-mass stars.