1D atmospheric study of the temperate sub-Neptune K2-18b

  title={1D atmospheric study of the temperate sub-Neptune K2-18b},
  author={Doriann Blain and Benjamin Charnay and Bruno B'ezard},
  journal={Astronomy \& Astrophysics},
Context. The atmospheric composition of exoplanets with masses between 2 and 10 M⊕ is poorly understood. In that regard, the sub-Neptune K2-18b, which is subject to Earth-like stellar irradiation, offers a valuable opportunity for the characterisation of such atmospheres. Previous analyses of its transmission spectrum from the Kepler, Hubble (HST), and Spitzer space telescopes data using both retrieval algorithms and forward-modelling suggest the presence of H2O and an H2–He atmosphere, but… 

Methane as a dominant absorber in the habitable-zone sub-Neptune K2-18 b

In their Letter, Tsiaras et al.$^1$ reported the detection of water vapour in the atmosphere of K2-18 b, an exoplanet of 7 to 10 Earth masses located in the habitable zone of an M-dwarf star. The

Can Carbon Fractionation Provide Evidence for Aerial Biospheres in the Atmospheres of Temperate Sub-Neptunes?

The search for signs of life on other worlds has largely focused on terrestrial planets. Recent work, however, argues that life could exist in the atmospheres of temperate sub-Neptunes. Here we

Atmospheric Dynamics of Temperate Sub-Neptunes. I. Dry Dynamics

Sub-Neptunes (planets with radii between 2 and 4 R ⊕) are abundant around M-dwarf stars, yet the atmospheric dynamics of these planets is relatively unexplored. In this paper, we aim to provide a

Disentangling atmospheric compositions of K2-18 b with next generation facilities

Recent analysis of the planet K2-18 b has shown the presence of water vapour in its atmosphere. While the H2O detection is significant, the Hubble Space Telescope (HST) WFC3 spectrum suggests three

High Accuracy Molecular Line Lists for Studies of Exoplanets and Other Hot Atmospheres

The desire to characterize and model the atmospheres of the many extrasolar planets that have been discovered over the last three decades is a major driver of current astronomy. However, this goal is

Inferring Shallow Surfaces on Sub-Neptune Exoplanets with JWST

Planets smaller than Neptune and larger than Earth make up the majority of the discovered exoplanets. Those with H2-rich atmospheres are prime targets for atmospheric characterization. The transition

Photochemistry and Spectral Characterization of Temperate and Gas-rich Exoplanets

  • R. Hu
  • Physics, Geology
    The Astrophysical Journal
  • 2021
Exoplanets that receive stellar irradiance approximately equal to Earth’s or less have been discovered and many are suitable for spectral characterization. Here, we focus on the temperate planets

Unveiling Shrouded Oceans on Temperate sub-Neptunes via Transit Signatures of Solubility Equilibria versus Gas Thermochemistry

The recent discovery and initial characterization of sub-Neptune-sized exoplanets that receive stellar irradiance of approximately Earth’s raised the prospect of finding habitable planets in the

Possibilities for an Aerial Biosphere in Temperate Sub Neptune-Sized Exoplanet Atmospheres

The search for signs of life through the detection of exoplanet atmosphere biosignature gases is gaining momentum. Yet, only a handful of rocky exoplanet atmospheres are suitable for observation with

How to Identify Exoplanet Surfaces Using Atmospheric Trace Species in Hydrogen-dominated Atmospheres

Sub-Neptunes (R p ∼ 1.25–4 R Earth) remain the most commonly detected exoplanets to date. However, it remains difficult for observations to tell whether these intermediate-sized exoplanets have



Methane as a dominant absorber in the habitable-zone sub-Neptune K2-18 b

In their Letter, Tsiaras et al.$^1$ reported the detection of water vapour in the atmosphere of K2-18 b, an exoplanet of 7 to 10 Earth masses located in the habitable zone of an M-dwarf star. The

Formation and evolution of exoplanets

Introduction Exoplanet Observations Pinpointing Planets in Circumstellar Disks Planet-Planet Interactions Formation via Disk Instability Core Accretion Model Formation of Terrestrial Planets Brown

TauREx 3: A Fast, Dynamic, and Extendable Framework for Retrievals

This work achieves dynamic determination of fitting parameters, whereby TauREx 3 can detect new parameters for retrieval from user code through a simple interface, with a sixfold reduction in retrieval times while maintaining robust results.

Resolution Molecular Spectroscopy

  • 2020

2019) observed (Benneke et al. 2019) nominal model ( 2 = 21.07

  • Tp, int =
  • 2019

Formation and Evolution of Exoplanets (NewYork: John

  • 2010

  • Ind. Eng. Chem.
  • 1947

ARES. II. Characterizing the Hot Jupiters WASP-127 b, WASP-79 b, and WASP-62b with the Hubble Space Telescope

This paper presents the atmospheric characterization of three large, gaseous planets: WASP-127 b, WASP-79 b, and WASP-62 b. We analyzed spectroscopic data obtained with the G141 grism (1.088–1.68 μm)

Consistently Simulating a Wide Range of Atmospheric Scenarios for K2-18b with a Flexible Radiative Transfer Module

The atmospheres of small, potentially rocky exoplanets are expected to cover a diverse range in composition and mass. Studying such objects therefore requires flexible and wide-ranging modeling

Tidal evolution of exoplanetary systems hosting potentially habitable exoplanets. The cases of LHS-1140 b-c and K2-18 b-c

We present a model to study secularly and tidally evolving three-body systems composed by two low-mass planets orbiting a star, in the case where the bodies rotation axes are always perpendicular to