Related papers: Self-Consistent Modeling of Metastable Helium Exop…
HAT-P-32 b is the first exoplanet for which absorption in hydrogen and helium lines has been measured simultaneously. In addition to the relatively large maximum depth of ~5% in both lines, observations have revealed very long pre-transit…
Over the last decade, precise exoplanet transmission spectroscopy has revealed the atmospheres of dozens of exoplanets, driven largely by observatories like the Hubble Space Telescope. One major discovery has been the ubiquity of…
Searches for helium in the exospheres of exoplanets via the metastable near-infrared triplet have yielded 17 detections and 40 non-detections. We performed a comprehensive re-analysis of published studies to investigate the influence of…
The near-infrared helium triplet line is a powerful tool for studying atmospheric escape processes of close-in exoplanets, especially irradiated gas giants. Line profile fitting provides direct insight into the mechanisms driving…
TOI-836 is a ~2-3 Gyr K dwarf with an inner super Earth ($R=1.7 R_\oplus$, $P=3.8$ d) and an outer mini Neptune ($R=2.6 R_\oplus$, $P=8.6$ d). JWST/NIRSpec 2.8--5.2 $\mu$m transmission spectra are flat for both planets. We present…
Radiative transfer equilibrium models of nearby interstellar matter (ISM) yield the boundary conditions of the heliosphere when constrained with observations of ISM inside and outside of the heliosphere. Filtration factors for interstellar…
Observed exoplanet transit spectra are usually retrieved using 1D models to determine atmospheric composition while planetary atmospheres are 3D. With the JWST and future space telescopes such as Ariel, we will be able to obtain…
Aims: We survey the transmission spectrum of WASP-121 b for line-absorption by metals and molecules at high spectral resolution, and elaborate on existing interpretations of the optical transmission spectrum observed with HST/STIS and WFC3.…
Hydrodynamic escape is the most efficient atmospheric mechanism of planetary mass loss and has a large impact on planetary evolution. Three hydrodynamic escape regimes have been identified theoretically: energy-limited,…
Exoplanet habitability is traditionally assessed by comparing a planet's semi-major axis to the location of its host star's "habitable zone," the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler…
The $\ion{He}{I}$ 10833\,$\AA$ triplet is a powerful tool for characterising the upper atmosphere of exoplanets and tracing possible mass loss. Here, we analysed one transit of GJ\,1214\,b observed with the CARMENES high-resolution…
Characterising the atmospheres of exoplanets is key to understanding their nature and provides hints about their formation and evolution. High-resolution measurements of the helium triplet, He(2$^{3}$S), absorption of highly irradiated…
Stellar high-energy radiation (X-ray and extreme ultraviolet, XUV) drives atmospheric escape in close-in exoplanets. Given that stellar irradiation depends on the stellar magnetism and that stars have magnetic cycles, we investigate how…
Precise atmospheric observations have been made for a growing sample of warm Neptunes. Here we investigate the correlations between these observations and a large number of system parameters to show that, at 95% confidence, the amplitude of…
Photoevaporation in exoplanet atmospheres is thought to contribute to the shaping of the small planet radius valley. Escaping atmospheres have been detected in transmission across a variety of exoplanet types, from hot Jupiters to…
Bathed in intense ionizing radiation, close-in gaseous planets undergo hydrodynamic atmospheric escape, which ejects the upper extent of their atmospheres into the interplanetary medium. Ultraviolet detections of escaping gas around…
Hot Jupiters orbiting extremely close to their host star may experience atmospheric escape due to the large amounts of high-energy radiation they receive. Understanding the conditions under which this occurs is critical, as atmospheric…
The internal composition of sub-Neptunes remains a prominent unresolved question in exoplanetary science. We present a technique to place constraints on envelope mean molecular weight that utilises observations of escaping hydrogen or…
During primary transits, the spectral signatures of an exoplanet atmosphere can be measured using transmission spectroscopy. The goal of this work is to accurately measure the atomspheric sodium absorption light curve in HD189733b,…
In recent years, it has become clear that a substantial fraction of transiting exoplanets have some form of aerosol present in their atmospheres. Transit spectroscopy - mostly of hot Jupiters, but also of some smaller planets - has provided…